IT must be understood, as I have previously intimated, that any enumeration of leaf-fungi as belonging to any particular month must be accepted as merely a convenient mode of conveying to the student what he should look for as most likely to be found. Nature does not accept any such limitations, and is only influenced by local conditions and by climate. For instance, the brand upon the Adoxa muscatellina (A. moschatellina?) I have usually classed with the fungi for June, and it is now in July in perfection, it is known as Puccinia saxifragarum (P. adoxae). Similar circumstances arise continually in every attempt at classification as to time.

I referred in the May paper to the genus Trichobasis. There are now various species of the genus to be met with, some, as the T. violorum (Puccinia violae), on the field violets, are very common, as is also T. cichoracearum (?) on the composite plants. Various other species also may now be met with, and are easily known and identified on microscopic examination. There are numerous Æcidiacei now to be met with, the one on garden mint as also on wild mint is very common; the same clustercup Æ. menthæ (Puccinia menthae) is found upon both, but is much more common on the garden mint than the wild. It grows chiefly upon the stalks, but occasionally it is to be found upon the leaves. There is one other clustercup of rare beauty which I have found this month, Æ. behenis (Puccinia behenis), or Bladder-campion clustercup. This fungus is rare as it is beautiful, and I have only found it twice, once in Wales and once in Devonshire, and in both cases on the sea coast.

Amongst the white micro-fungi, for we have them of all colours, there is one which I hunted for during almost a generation, and I have never met with in the north of England. It is Cystopus candidus (Albugo candida)on cabbage. I did, however, meet with it in Devonshire, in 1879, and in the following autumn at Deganway, near Conway in Wales. Strange to say there is the exactly same species of fungus which grows upon the Shepherds' Purse (Capsella bursa-pastoris) in great plenty almost everywhere. At certain times the plant and the fungus are alike common. There are other species of this genus which will often be met with by the industrious student, one of which is rarely found in perfection or in any considerable quantity. I allude to the Goat's beard cystopus, known as Cystopus cubicus (Albugo tragopogonis), or Goat's beard white rust. This I have found in small quantity near Southport on many occasions, but I dont imagine that it is ever developed in large quantity. On cabbage, when cystopus is found on that plant, it appears in patches often comparatively large, and they have the appearance of dabs of whitewash.

There is another genus to which I desire to refer, although several of the species are, from their surrounding conditions, difficult to meet with. Others cannot well be overlooked. Amongst the latter are Tilletia caries (T. tritici), the bunt of wheat, and Ustilago carbo (U. segetum), corn smut, so common on oats and barley. Amongst the more minute species are those that grow upon the anthers of various flowers. Ustilago Antherarum (U. violacea) I have but once found; it was when I was botanizing in Dovedale some years ago; it was on Silene inflata (S. vulgaris). In the summer of 1880, I for the first time met with Ustilago Kuehniana (U. kuehneana) at Urmston on anthers of common Sorrel, Rumex acetosa. Ustilago longissima (*) on grass I have frequently met with, but only in one locality, near Nortbenden in Cheshire; but I don't suppose the smut is confined to any county whatever. When seen upon the leaf it wears the appearance of fine black lines as if I ruled with a pen. There are various other species on grass, as also on numerous plants, and they are all worthy of being sought after by the reader.

These very minute organisms require a good lens of high power, and also of good defining quality, in order to distinguish the different species. I have often employed one of Beck and Beck's one sixth for this purpose, and even then I have had to go over the specimen frequently before I could come to any satisfactory conclusion.

Now is the time to begin to look out for Peronospora. They generally assume the form of delicate white threads thickly set upon the leaf of the plant, giving it a somewhat glazed appearance. One of this genus is the great enemy of our favourite vegetable the potatoe, and is the especial dread of the market gardener. If the season be wet, this well-known mould Peronospora infestans (Phytophthora infestans), as it is named, is very likely to be developed towards the latter end of this month, or early in the next. A preliminary decay of the leaf is indicated by the appearance of brownish spots, and on the examination of the leaf in this condition, the mould, if existing, will be found close to, and sometimes partly upon the spots. Unfortunately this pest is far too common amongst potatoe fields in wet seasons. In August, 1880, I met with an enormous quantity of the fungus in potatoe fields at Urmston, and, had not the farmers took the wise step of at once digging up the tubers, the destruction would have been fearful. Thoughtless delay in the farmer frequently gives the fungus time to get down to the potatoe itself, when the tuber quickly becomes unfit for human food. The way by which this rapid change comes about, is a good study for the microscopist, but is too long a story for me to tell on the present occasion. The species of this genus are numerous, and new ones are frequently being found;; some ten or a dozen such are well recognised and admitted as true Peronospora that were not known a dozen years ago. The Rev. Mr. Vize, of Forden, Welshpool, has the honour of bringing some of these to the knowledge of botanical students. If the reader desires, he may soon collect a considerable number of the Peronspora, for they are constant visitors upon a large number of our plants. Our old friend Ranunculus ficaria, which has already given us a beautiful clustercup Æcidium ranunculacearum (Uromyces dactylidis), and the smut Uromyces ficariæ (*); supplies us with a Peronospora, P. ficariæ (*). The wood anemone also gives us a clustercup, Æcidium leucospermum (Ochropsora ariae) and a smut Puccinia anemones (Tranzschelia anemones) now presents us with the Peronospora pygmæa (Plasmopara pygmaea). In this way numerous plants during the year come forward from time to time with their contributions for scientific study. I think I can now best assist the student by giving a list of the more common Peronospora, a familarity with which will tend to educate the eye, and prepare him for the discovery and identification of the more rare ones. The more common ones, speaking from my own experience, are :-

Peronospora nivea (Plasmopara nivea) (Parsnip mould), on Umbelliferæ.
P. gangliformis (Bremia lactucae) (Lettuce mould), on Lettuces and other compositæ
P. vinciæ (P. viciae) (Pea mould), on Peas, &c.
P. violæ (*) (Violet mould), on leaves of common Violet.
P. urticæ (Pseudoperonospora urticae) (Nettle mould), on leaves of Nettle.
P. obliqua (P. rumicis) (Dock mould), on leaves of Sorrel and Dock.

Amonst the Æcidiacei we have several interesting fungi, known as Peridermiums, one of which Peridermium pini (Cronartium flaccidum) may be found this month on leaves of Scotch fir. I cannot but think it very rare, as I have never been able to meet with it, although my attempts in that direction have been continued from year to year ever since my study of these wonderful plants began. Let the student, however, take such opportunities as he may have for the examination of the tree, and it is not improbable that he may be more fortunate than the writer.

CERTAIN members of the interesting group of micro-fungi, known as Pucciniæi, have had our attention in previous papers as they have been gradually coming to the front. Now we have them in great plenty. The straw stalks of wheat and the leaves of wheat, as also certain grasses, are frequently infested with a member of the group known as Puccinia graminis (*), the spores of which, like those of other Puccinia proper, are two celled, but they are larger and much longer than most if not all other members of the group, and possess a lengthened stalk or peduncle. Garden mint is now likely to develop a Puccinia, for I have found it yearly during some eight or ten years about this time in a neighbour's garden, on the outskirts of Manchester and elsewhere. This smut Puccinia menthæ (*)is also found on wild mint and other plants, but it is more rare on the wild than the garden mint. P. glomerata (*)is to be found on the ragwort now, and will continue with us almost to the end of the year. It must, I think, be very common, for I have met with it so frequently round about Manchester as also far away from that city. The species of ragwort, Senecio jacobæa, on which I have usnally found the smut, is one of our most common wild plants.

Puccinia variabilis (*), which infests that common weed the dandelion, claims our special attention from the circumstance of the strange variations which exist in the forms of its spores. Some are rounded, others stunted or variously elongated, while occasionally they are formed of three cells, whereas the common characteristic of Puccinia is that they are two celled. It is but seldom that I have met with this singular variation of three cells from the normal condition of the spores. In some portions of the country the fungus is very common, and I have found almost every leaf infested, in others it is very rare, if ever met with. This is the case in Lancashire and Cheshire so far as my experience goes.

Belonging the Pucciniæi there are several species of another group of leaf-fungi which have a special claim upon our attention. I allude to those known as Phragmidiums. They may all be met with about this time, but some in favourable localities will have appeared earlier, while others will linger on even a month or two longer. Instead of being two celled like the Puccinia, they are made up of three, four, five, or in some instances six cells, thus forming a small string of cells. Upon the leaves of plants where they grow they assume an aggregated appearance and form tufts, and well dried and mounted in this condition as opaque objects make most charming slides for the microscope. The whole of the group have peduncles or stalks of attachment to the leaves upon which they grow, and as they are not. numerous I will refer to the whole of the known British species.

The most conspicuous of the group is the bramble brand, Phragmidium bulbosum (P. bulbosum and P. violaceum), and it is very common over a largeextent of country,especially in Wales and the Lake District. In other localities I have met with it - as for example - in Cheshire and Derbyshire, but in these cases always in smaller quantity. The P. bulbosum I have found as late as October on one occasion, as also I, on the same occasion, met with raspberry brand - Phragmidium gracile (P. rubi-idaei). In those two instances the plants were in fair condition, although the season was so far gone. The raspberry brand is a smaller fungus than the bramble brand, and the reader will find the distinction most marked, besides the leaves of the two plants at once determine the question. The leaf of the bramble is prickly and of a coarser structure than the leaf of the raspberry.

The Rose brand, Phragmidium mucronatum (*), is not so common as the two other brands I have already named, but still it cannot be called scarce, for in favourable localities it is plentiful. In the open country at the proper time it may be found by the st udent upon the leaves of the common dog rose. The best find I ever made of this Phragmidium was near Southport some ten years ago about this time. I have met with it frequentlyelsewhere, but never upon the cultivated or garden rose.

The Strawberry brand, Phragmidium obtusum (P. fragrariae on Potentilla sterilis), and the Burnet brand, Phragmidium acuminatum (P. sanguisorbae), are both somewhat smaller fungi than those previously named. The first is found on the leaves of the wild strawberry plant. I have met with it on two occasions in moderate quantity, but I am inclined to think it rare. One occasion was when I was at Aberystwith, and the other within about a mile of the sea coast in the Lake District. The P. acuminatum is a still rarer fungus, and when found upon the leaf of the burnet is generally in small quantity, and very likely to be overlooked by the student. It is in a case of this kind that a good pocket lens is extremely useful. We have another member of this group named by Dr. Cooke, Phragmidium bullatum (P. mucronatum). This fungus is said to grow upon the twigs of the dog rose, but as yet I have not had the good fortune to meet with it.

I have just spoken of Phragmidium acuminatum (P. sanguisorbae) as growing upon the burnet. It should however be remembered that it is the smaller burnet, Poterium sanguisorba (Sanguisorba minor), upon which the fungus grows, for we have a larger burnet, Sanguisorba officinalis, and this also furnishes us with an interesting brand - I allude to the charming chain brand, Xenodochus carbonarius (*). This is 'one of the most pleasing and interesting of all the leaf-fungi, and is said by Dr. Cooke to be very rare. Notwithstanding this opinion of the Doctor, I have to say for the encouragement of the reader that I find it every summer in plenty. My chief gatherings have been in the Buxton valley some two or three miles from the town. I can any summer find it also in Cheshire in the valley of the Bollin in fields near the river. I have received it from Montgomeryshire, and I doubt not it may be found in numerous localities. The brand has the general characteristics of a Phragmidium, but it is greatly extended in length, and forms a beautiful chain as of beads, a sort of fairy necklace. Besides this there is still a smaller chain brand, I allude to Xenodochus curtus (?[Grove (1913) says 'not a rust, maybe a species of Hyphomycetes]), which has never been found but once when the writer had the good fortune to meet with it in September, 1873. Specimens of the fungus were forwarded to Dr. Cooke, and he has in the later editions of his work, " Rust, Smut, Mildew, and Mould," given a full description of the plant to which I beg to refer the reader. The plant upon which it was found is Valeriana officinalis, and it will give me pleasure if I can hear of other students meeting with this very rare fungus. For the information of the reader, I will explain the locality in which I met with it. On the high road from Buxton to Bakewell there is the village of Taddington, about equal distance betwixt the two places. Going in the direction of Bakewell from Taddington and about a mile from the village is a wood on the left hand or eastern side of the road. It was in this wood and not many yards from the road that I found Xenodochus curtus. I have made many efforts since my discovery to find more of the fungus, but I regret to say always without success.

The reader will find August a favourable month for gathering another curious group of leaf-fungi, known as Erysiphe. The general structure and physiology of these fungi differ greatly from all others that have claimed our attention. Their appearance as seen on the leaves of the plants upon which they grow is that of small cannon balls, and they are most difficult to find on account of theirextreme minuteness. The one on the burdock - burdock blight, Erysiphe montagnei (E. depressa), is I think the best to find on account of the large quantity and comparative largeness of the fungus. Whenever the reader meets with the leaves of the burdock in a decayed condition, he will most probably find such leaves infested with the fungus in an unmistakable manner. The mugwort is infested with a much smaller fungus, Erysphe Linkii (E. artemisiae). This I have found in numerous localities in Lancashire and Cheshire, and I have reason to look upon it as common. We have one member of this group on peas and beans and various other plants. It is known as Erysiphe Martii (E. pisi), and is very common in autumn. Besides those I have already named we have Grass Blight, Erysiphe graminis (*); we have the Composite Blight, Erysiphe lamprocarpa (Erisyphe sordida), on plantain, and sundry other plants; we have the Buttercup Blight, Erysiphe communis (E. ranunculae), and the Bugloss Blight, Erysiphe horridula (E. cynoglossi), and lastly Cornel Blight, Erysiphe tortilis (*). The last, which is to be found upon the leaves of the dogwood, Cornus sanguinea, I have met with but once. Still I don't think it scarce, but its extreme minuteness makes it difficult to find. One peculiarity of this group of fungi is that they are surrounded with singular radiating appendages, an idea of the general characteristics of which may be gathered from the figure [6] on Plate No. 1. Another is that the spores of the fungus are developed in a sort of pod called an ascus, each ascus containing two spores [6a Plate 1]. If the student desires to see the spores in ascus he should take one or more of the parasites from the leaf, place them in water and burst them by pressure when under the microscope, when he cannot well fail to find what he is looking for, as also the remarkable appendages connected with the parasite.

THE autumn of the year is the great harvest of the student who pays especial attention to micro-fungi. It is then that the leaves of trees, and vegetation generally, begin to decay under the blighting influence of a lower temperature, and as they lose their vitality they become the abodes of a new vegetable kingdom, which may not improperly be called the invisible kingdom, for so far as the world generally is concerned, it is altogether unknown and uncared for. With the decay of ordinary vegetation we lose one of the most lovely aspects of nature, but to the microscopist this is not altogether a loss; there is a happy compensation for him in the marvellous wonders he finds in the new world brought into existence by the decay of the old. In the earlier portions of the year the micro-fungi he was able to find were upon healthy, perfect leaves, and comparatively few; now their number is legion, and they are found on dead and dying vegetation all around him wherever he may care to look for them. It would be vain in me to attempt to refer to all the numerous species which now make their appearance: the catalogue would be far too long for this short article, so I must confine myself chiefly to the notice of what I have myself met with in my rambles, or such as I have come upon unexpectedly. Still, as almost every locality is the home of special plants, microscopic or otherwise, it may be well to refer to such micro-fungi as may be easily recognised, by the student.

By this time most of the Uredos are over, the one on the larger burnet still lingering on in connection with the beautiful chain-brand referred to in the last number for August, hut several others have come to the front, amongst them Uredo quercus (*). On the underside of oak leaf this has been found in Sherwood forest and elsewhere, but I have never heard of it being found near to any of our large towns. The same remarks will apply to the bilberry fungus, Uredo vacciniorum (Pucciniastrum vaccinii), which is a native of the mountains or the moors. The fern uredo, or Uredo filicium (Hyalospora polypodii), I have met with frequently on Cystopteris fragilis, but I still believe it is rare, as I cannot hear of others finding it. I have a. specimen on Scolopendrium vulgare which was supplied me by a friend.

Amongst what may be termed the autumnal Uredos is one (Puccinia circaeae)on the Enchanter's Nightshade, Circæ lutetiana. This I once met with in beautiful condition in a wood at Matlock. The wood is on the left bank of the river Derwent, which has to be crossed by a boat. There is a remarkable circumstance connected with all these later Uredos, namely, that the spores are extremely minute. If the student will be at the trouble of comparing the spores of Uredo miniata (?), or any of the earlier species, with the spores of any autumnal kind, he will at once recognise the great difference.

Many of the fungi referred to in last month's paper are still to be found, especially Erysiphe montagnii and E. Linkii. Last year I found these in great plenty as late as October. It is only when the plants on which they live have been destroyed by the frost that they altogether disappear.

Amongst Pucciniæi named in former papers, some are over, but many remain to reward the botanist, and amongst them are many that I have not previously referred to; amongst them Puccinia polygonorum (P. polygoni-amphibii). This I have never met with in good condition but once, and that was so far back as the autumn of 1863, now eighteen years ago. Puccinia galiorum (?P. punctata [but two possible species]), Bedstraw brand, on Galium aparine should be looked for now and also in October, as I found it last year in the latter month. The asparagus brand, P. asparagi (*), may now be met with. I have once found it when stopping at Ashford-in-the-Water, near Bakewell. The Iris Puccinia, and others named by Dr. Cooke I have never yet been able to find.

In looking over my own gatherings of micro-fungi I have frequently been reminded of the fact that a considerable number of them I have met with but once, while others come to the front every year as regularly and as plentifully as dasies or buttercups. Some that I once thought very rare I now find frequently, and some others that I felt inclined to think common I have never met with. Probably this also maybe the experience of other students. The only wise plan of research is for the student to look out everywhere whenever an opportunity arises in both likely and unlikely places, and he will not unfrequently be rewarded by finding in the latter unexpected treasures, which will amply repay him for any trouble he may have taken.