Royal Microscopical Society. 143 



Not knowing of any plant that corresponded with the above, and 

 supposing it to be some form of mildew that had formed on the 

 dead moss, before incrustation, the writer was disposed to regard it 

 as belonging to the Mucoroideae. Fortunately, however, having left 

 a mounted slide in the hands of the Assistant-Secretary, Mr. Walter 

 Reeves, he kindly promised to try and obtain the opinions of others 

 more versed in these matters. The slide was shown by him to my 

 friend Mr. Slack, who has been much interested in the subject, and 

 thus expresses himself, in his note of January 19th, which I take 

 the liberty of quoting. He says, " The bodies certainly look much 

 like fungi, with asci full of spores, but I have never met with and 

 cannot find in Berkeley or Cooke any that have such mycelium 

 threads or such asm." " The round bags in your objects are evidently 

 strong and thick ; their fractured edges, I think, leave no doubt of 

 this. The tubes also seem much firmer and with a more decidedly 

 cortical layer than any I know of in fungi." " Although I cannot 

 refer them to any other class, I should doubt their being fungi 

 unless we had some undoubted fungi in a fresh state and sufficiently 

 resembling them, to strengthen that view." " Their interest is 

 undoubted," &c. 



Mr. Reeves also brought it to the notice of Mr. Renny, and thus 

 kindly writes on February the 10th, " Mr. Renny thinks the little 

 plant is not a fungus, but probably a species of Botrydium, a genus of 

 confervoid Algae, only one species of which has as yet been found in 

 England, and very little is known about it." He thinks " it would 

 be found growing on the banks of the stream near where your 

 deposit was obtained." To Mr. Slack I am indebted for procuring 

 the opinion of Mr. Currey, who also examined the specimen and 

 was disposed to agree with Mr. Renny. With permission I beg to 

 quote the remarks in his note of February 20th : — " I am decidedly 

 of opinion the object is not mucedinous, nor does it, I think, belong 

 to any class of fungi. It seems to me to be certainly an alga allied 

 to Hydrogastrum (Botrydium) and Vaucheria. The chitinous 

 appearance I think only arises from the brown colour which is 

 common on decaying filamentous Algae," and adds " no truly micro- 

 scopic species of Botrydium has hitherto been described, at least to 

 my knowledge." 



At the same time Mr. Slack pressed me to make further exami- 

 nations, and contribute the same to the Royal Microscopical Society, 

 in conformity with which, I have been induced to spend a consider- 

 able time in the further elucidation of the subject, and endeavouring 

 to secure good specimens for figuring. 



Although the masses had been found beneath water, it seemed 

 just possible that this part of the foot-bed of the spring might occa- 

 sionally be dried up, and that if the fine Botrydioid structure had 

 formed on the incrustations at such a time, that I should be able to 



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