20 PROCEEDINGS OF SOCIETIES. 



of extreme fineness), and from the surface of the growth, one of the cells deve.oped 

 the new shoot, which resembled in all thinprs the parent plant. It remains now to 

 describe what 1 believe is new, at least as far as ray researches go — the fact that this 

 unicellular rapidly developing condition of the plant is perfectly capable of destroying 

 life in fish ; many, indeed almost all of them, which have recently died with me, and 

 I have now lost all my fish but three, have presented this state of plant alone (at 

 least during life). It adheres in dense masses to the fins, the tail, and even to the 

 edges of the scales over the body ; it collects on the gills, disorganises them, breaks 

 down the higher organised tissues, lays bare the cartilaginous structures in the gills, 

 tail, and fins, and interfering with respiration (as it seems to me), proves even thus 

 more rapidly fatal than from its more slow but equally certain destructive action on 

 the vital tissues. It is impossible not to recognise in this, which might be termed 

 a " mycelium stage," a strong analogy with the mycelium stage of fungi. We 

 know how dry rot, for instance, produces its destructive ravages in wood in its 

 rapidly growing mycelial condition, not in its more advanced state of development, 

 and I have in my researches on this subject become strongly impressed with the 

 conviction, that it is to this as yet unrecognised state of the Saprolegnia we are in 

 reality to ascribe much, if not all, of the destructive action which it exerts on animal 

 life. In fact, I believe we have in it a clear instance of a plant causing disease in 

 healthy bodies, and not, as is too commonly believed, a mere vegetative growth 

 developed on a body already in a state of ill health. Such is, indeed, the general 

 doctrine held with reference to Epiphytic growths occurring in disease, which are 

 frequently regarded as accidental Epiphajnomena ; whereas their invariable presence 

 alone in such cases would of itself go far to the unprejudiced mind to prove a more 

 intimate connection between them and the diseased condition which they accom- 

 pany, or, as I think, frequently produce. 



Mr. Williams corroborated the fact of the destructive properties of this disease, as 

 exemplified in gold fish formerly in his possession, which were completely smothered 

 by it. He attempted to destroy the disease by removing the diseased spots, but in- 

 effectually. 



Mr. H. Barton mentioned that some years since he found that some minnows 

 and sticklebacks which he had in confinement died of this disease ; they had been 

 fed for some time previously on bread crumbs, after which he had placed them in a 

 vessel with some gold fish. These latter remained perfectly free from the disease, 

 though all the minnows and sticklebacks died. 



Dr. Kinahan had seen this disease in the following aquatic animals while in a 

 state of freedom and alive ; gudgeon, Gobio fluviatilis ; loach, Cobitis barbatula ; eel, 

 Anguilla acutirostris (young), stickleback, Gasterosteus leiurus ; fry of salmon, 

 Salmo salar, and trout, Salmo trutta, and in the smooth newt, Lissotriton punctatus. 

 During one season it was so prevalent in one part of the Dodder, that nearly all the 

 salmon and trout fry were destroyed by it ; he had also seen it on the larva 

 of the dragon-fly. 



Mr. Williams read the following 



ON A REMARKABLE CHANGE OF COLOUR IN A FOWL OF THE HAMBURGH BREED- 



Gentlemen, I beg leave to bring before your notice this night a re- 

 markable change of plumage in a hen of the Hamburgh breed, which is 

 painfully recorded in my mind, from the fact, that, by whatever affected, whether 

 fright or otherwise, I lost the chance of the silver cup in the crested class at the 

 last Liverpool show in January last. When I selected this bird in the beginning 

 of January, as one of a pen fit to compete, she was then perfect in the markings 

 so characteristic of her variety, each feather being accurately marked, as well as 

 having her legs blue, which is the proper colour of the breeds. The lot was not 

 commended, and on examining the several pens at the show with a critical ama- 

 teur, and discussing the several merits and why this pen was passed by unnoticed, 

 he pointed out what, in his opinion, was the cause, viz., that the legs of this bird 

 were white, as he could not detect any other defect ; in this view 1 was obliged to 

 acquiesce, but I was not the less astonished, thinking it impossible that I could 



