in order to study the richer mycological literature to be found there. There he delivered to the printer the first part of his "Observationes Mycologica," to which the harvest of fungi of 1813 had given the chief materials. In 1814 he began, principally by the counsel of Ol. Swartz, to write his "Monographia Pyrenomycetum Sueciæ," which work he presented in 1816 to the Academy of Sciences in Stockholm. Shortly before he had published his second volume of "Observationes Mycologica." In this manner Fries began his mycological studies. But soon he found that the method pursued till now in describing and systematizing was not at all satisfactory, and therefore he began, in 1816, to work out a new system, and subject all the fungi to a fresh investigation,—a labour connected with the greatest difficulties, both because the construction of the microscope was at this time very imperfect, and because no good method of conservation was known for fungi. This new system was based upon the most minute examination of the appearance of the fungi in different stages of the development, and of the morphological importance of the different parts. It was received with universal approbation, and became the foundation of a new science. A great number of works on the different groups of fungi, and the first part of his "Systema Mycologicum " came next. Every summer he walked through the woods in the southern part of Sweden. He longed in vain to extend his pilgrimages to foreign countries, his own resources being too small and no public stipend to be had. But fungi in great quantities were sent him from foreign countries, and he gave descriptions of them in "Elenchus Fungorum." In 1828 he was at last able to visit the northern part of Germany and the museum at Berlin, when he had opportunities of enlarging still more his knowledge of lichens, of the foreign fungi, and of the literature of these plants. During the following years he completed his "Systema Mycologicum," and having done this, he subjected the fungi once more to a close investigation, comparing them with his own descriptions. When they had been thus revised and completed, the Discomycetes parted from the Hymenomycetes, &c., the results of his observations were published in "Flora Scanica" in 1835. Having changed his abode to Upsala, Fries found new fields for his mycological studies, and was as indefatigable as before in his excursions. Working industriously he wrote "Epicrisis Systematis Mycologici seu Synopsis Hymenomycetum," published in 1838. He intended also to give a new review of the Ascomycetes, with several hundred determinations of species, but this part of the fungi not being much estimated by his contemporaries, he was obliged to desist, and continued with the Hymenomycetes, which were generally embraced with greater sympathy. In the year 1844 the Academy of Science in Stockholm resolved to be at the expense of a series of engravings of all the species of fungi, principally belonging to Hymenomycetes, that could be preserved in a natural state, and gave the superintendence and direction of this work to Fries. It was the fourth time he had occasion to subject these fungi to close observation. This collection, containing now 1600 to 1700 coloured engravings, is the richest and most expensive existing in any country. Eleven volumes, with 110 plates, have been published, with the title "Icones selectæ Hymenomycetum nondum delineatorum." It is probably one of the most elegant engraved works existing in botanical literature. The last large work of Fries was "Hymenomycetes Europæi sive, Epicriseos systematis mycologici editio altera," published in Upsala, 1874. He had also, already at an early age, studied the lichens no less thoroughly, and essentially reformed the description and systematisation of these plants. His "Lichenographia Europæa reformata," published in Lund, 1831, was for a long time regarded as a principal work in lichenographic literature, and the numerous fasciculi of his "Lichenes exsiccati Sueciæ " make one of the most excellent dried collections that are to be had in this branch. The literary activity of Professor Fries has brought forth fruit in almost all the fields of botany. He has published explanations and critical examinations of some rather difficult genera among the higher plants, for instance, Hier TRANS. BOT. SOC. VOL. XIII. 2 c acium, Salix, Carex, and several others. He has written floristic works on all Scandinavia, and on separate parts of it; he has given (in "Novitia Flora Suecice," "Botaniska Notiser," &c.) descriptions of a great many new plants discovered by him. He has written treatises on agriculture and practical botany, on the nomenclature of plants and the history of botany; I may also mention the "Botaniska Utflygter" ("Botanical Excursions"), in which he has in a very happy manner popularised his science, and in which all Europeans of education have followed him with lively interest. All these works prove a scientific productiveness and importance which is not likely to find many parallels in botany, excepting Linné. Fries was very proficient as a botanical systematiser also, and the Friesian system is still followed by some Swedish botanists. It is true that other principles and opinions on the relation of the species to each other will probably take its place; but nevertheless it had a great importance, and must be counted among the most excellent of those natural systems in which the same point of view has been taken, that Linné describes in these words, as being his own: "A species is each form brought forth by the Creator in the beginning." It is but natural that some of the books of Fries have not the same authority now as when they first saw the light, science having since then sped forward with such swiftness that some parts of them belong only to the history of botany. But even this swift speed is the highest proof of their value. For it was his works that gave the impulse to those labours that have in our days given quite another form to the separate branches of botany. The power that Fries possessed of giving, in writing, clear and well-defined expressions of his scientific opinions, also distinguished him in his lecturing, and had a great part in gathering round him great numbers of disciples. The foreign pursuers of science who visited Upsala during the last forty years of his life seldom neglected making the personal acquaintance of the celebrated botanist. This lively interest in his science, and his affectionate regard for every one who pursued it, procured for him the veneration and love of all, and those who participated in a more con fidential intercourse with him cannot praise their fortune enough, feeling most happy in having made the acquaintance of a man so noble and good as Fries. His enthusiastic love of his science followed him, as it were, from the cradle to the grave. He continued his useful scientific labours during the last years of his life even as an author. In his eightieth year he published a new and changed edition of his extensive work, "Hymenomycetes Europæi," and about a week before his death he completed an essay for a continental periodical. Even far into his last hours he contemplated with interest and comprehended clearly the figures in the second number of Dr M. C. Cooke's "Mycographia," and said that some of the fungi were unknown to him. "England," he said, "has more remarkable Discomycetes than Sweden, but as regards Hymenomycetes we take by far the lead." Some hours later his eyes were closed for ever. It was on the evening of the 8th of February 1878. In the Royal Society's Catalogue of Scientific Papers there are enumerated eighty-five separate publications by Fries, extending from the year 1816 to the year 1874. I. Notes on the Salmon Disease in the Esk and Eden. By GEORGE BROOK, ter., F.L.S., F.R.M.S. (Received 6th April and read 12th June 1879.) In May last I published in the "Naturalist" a rough sketch of the course of development of this disease, and somewhat later Mr A. B. Stirling communicated to the Royal Society of Edinburgh a paper on the same subject. His conclusions were in many cases at variance with mine, and, as my conclusions had been questioned in other quarters, I thought it advisable to go over the subject again. My first acquaintance with the disease was in February 1878, when Mr Tyson Pattinson kindly sent me a diseased fish to examine. In the early part of April I spent a week in the neighbourhood of Carlisle for the purpose of inquiring into the cause of the disease, and have since carried on experiments on fish in confinement. I need say nothing as to the scientific position and life history of the fungus which causes the disease (Saprolegnia ferax); this has been admirably worked out by Pringsheim, Cornu, and others. In the specimens I examined in the spring the fruit-heads (the reproduction by zoospores) were club-shaped. In the autumn they were shorter and more rounded. On a specimen which I kept under the microscope for six weeks this was particularly noticeable, and may have been due to the want of sufficient nourishment, though I scarcely think this the sole cause, as the fruitclubs, if not large, were unusually abundant. The true sexual reproduction by which the resting spores are produced seems to be of rare occurrence, and to take place only at a later stage in the plant's development. I have observed it more frequently in specimens kept in confinement than in those taken from the fish in the rivers affected. Cornu ("Ann. Sci. Nat.," 1872) lays great stress on the zoospores as one of the distinguishing features of Achlya and Saprolegnia. In Saprolegnia, he says, the zoospores are usually emitted as ciliated cells, which, after a certain period of motion, settle down and develop a new plant, but that occasionally, under certain favourable conditions, the zoospores are emitted as spherical cells, furnished with a cell-wall, and that these, after a period of rest, burst and emit an active zoospore, which goes through the usual course of development. In Achlya the form of zoospore, which is the exception in Saprolegnia, is of most frequent occurrence- the other forming the exception. In the specimens I have examined, the zoospores, as far as I have seen, have, on the bursting of the fruit-club, clustered round the opening as spherical nonmotile cells, and have only assumed the active condition after some time. I have seen several fruit-clubs burst, and have not in a single instance seen the zoospores swim clear away; they have always clustered together as a globular mass first. In this respect they resemble Achlya, but other characters show that the fungus must be referred to Saprolegnia ferax. From February to May 1878 the papers were full of letters describing the ulcerated, evidently painful stage of the disease-how that fish were seen to dash and writhe about on the surface of the water, knock their heads against stones, and thus put an end to their miseries. No doubt there is some truth in these accounts, but to me many of |