242 The Scottish Naturalist. 



twisted, or collected into inextricable coils, and they may be simple 

 or may branch slightly. They give the usual reactions when 

 chemically treated, and show an exceedingly delicate membrane 

 or wall. Usually, the masses give off branches which surround 

 the nuclei of the cells of Juncus, or bore through from cell to cell 

 to form masses anew. The spores are produced at the tips of 

 wavy or spiral branches, thinner than the ordinary branches from 

 which they arise. They become round, and thereafter become 

 oval, and reach an average size of about -02 by '017 mm. 



The spore is enclosed in a wall of two layers — the inner is thin 

 and delicate, while the outer becomes covered with rather large 

 low warts, and is deep yellow or red-yellow in colour usually, 

 though sometimes it remains pale. The spores mature in order 

 of succession from the base of the tumour towards the tip. They 

 remain in the tumour all winter after its tissues have become dis- 

 organised. 



I have found these tumours common on the roots of Juncus 

 bufonius in one spot on the sandy links across the Don ; and I 

 have also gathered them at Park on Deeside. In both localities 

 they were as described above. Professor Balfour told me a week 

 ago that he had this summer found considerably larger branching 

 tumours in the neighbourhood of Glasgow, on what he believed to 

 be the roots of Juncus lamprocarpus. Probably these are also 

 caused by the same or by a closely-allied fungus. 



The earliest notice of the tumours ony; bufo7iius was published 

 by Professor Magnus in the Verhandl. d. hot. Vereins d. Prov. 

 Brandenburg, 1878, p. 53, in which he described them briefly, and 

 named the fungus in them, and in similar tumours on roots of 

 Cyperus flavesccns, from near Berlin, Schinzia cypericola, 



Herr C. Weber, a pupil of Professor De Bary, has recently (13th 

 June, 1884), published in the Bota?iiscke Zeitimg (vol. xlii. pp. 

 369-79, t. 4), a valuable paper on this fungus, worked out on 

 material from J. bufonius obtained near Strassburg. From that 

 paper I take the following additional information, insufficiently 

 shown in my specimens : — 



Experiments with the spores show that germination begins only 

 in the spring following their production. It is easily brought about 

 by placing them on a damp stratum. From each spore one or 

 more (up to four) promycelia proceed, with no regularity of origin, 

 but bored through the epispore anywhere. They may become five 

 times as long as the diameter of the spore. They are usually 

 simple, and almost always wavy. They may show a division wall 



