998 RECORD OP CURRENT RESEARCHES RELATING TO 



life being a species of Bacteria. They are small discoid-looking 

 bodies, which in this case I find imbedded in, and moving amongst, 

 the striated muscle-fibre of the fish, and when, by pressure or other- 

 wise, they are forced into the surrounding fluid, they have a power of 

 motion, moving mostly in a sort of circular direction. In some fish that 

 I have examined, I observed that the muscle was almost detached from 

 the strong fibro-muscle layer of the skin, and the muscle fibres of that 

 layer were not adhering together as in their natural state, and could 

 be separated from each other like threads by the needle. Whether 

 that diseased condition of that part of the skin was caused by the 

 muscle immediately below it, or by the fungus on the surface, I am 

 not in a position to say." Afterwards he says : — " The disease was 

 located in the muscle of the fish, and I also have some idea that it 

 will be found to commence in the blood, caused either by the food 

 they eat, or by some deleterious solution in the water which passes 

 through the gills ; and that the unhealthy decaying fluid or matter 

 which will naturally pass off from those Bacteria, and exude through 

 the pores of the skin, forms a healthy and proper nidus for the ger- 

 mination of the zoospores of the fungus, which must be in those affected 

 rivers in myriads." 



It would be some consolation to the mycologist if, after all, he 

 could feel convinced that this fatal salmon disease was not primarily 

 caused by the Saprolegyiia ; but Dr. M. C. Cooke considers that 

 " there are very grave doubts whether these Bacteria are not more 

 probably the result of a certain disintegration of the substance of the 

 flesh caused by the mycelium of the Sajprolegnia, than a preliminary 

 depravity of the flesh inducing the subsequent development of the 

 fungus. However much we may dislike the conclusion that a fungus 

 is the principal cause of so much mischief, I fear that we must accept 

 the force of evidence which goes to show that the Saprolegnia appears 

 to be the great destructive agent in this disease. It may be true, and 

 undoubtedly is, that the constitution of the fish is in a low condition, 

 that it is debilitated, and powerless to resist the fungoid attacks ; and 

 that this condition may be the result of various secondary causes ; 

 but the theory that Bacteria in the fish is the primary cause, though 

 it may be a new suggestion, can scarcely be accepted as a true one. 

 The coincidence should be borne in mind, even if it is no more than 

 a coincidence, that in all the great instances of devastating fungal 

 diseases, there has been an undoubtedly weakened constitution in the 

 subject, caused by over-cultivation, and in-breeding, preliminary to 

 the attacks. Such was the case with the silkworm, and it fell a prey 

 to ' muscardine ' ; in the potato, and it succumbed to the Peronospora ; 

 in the vine, and it became the victim to Oidium. May we not add 

 also, in the salmon, ere it was devastated by the Saprolegnia ? and it 

 may yet be to the onion in Europe, and the poppy in India, unless 

 the threatened misfortune should be averted." 



Biology of the Schizomycetes.* — H. v. Boehlendorff has applied 

 Bucholtz's method of investigating the life-history of the Schizomy- 



* Bnehlendoi-ff, H. v., ' Ein Beitrag zur Biologie einiger Scliizomyceten. 

 Inaug.-Dissert.' Dorpat, 1880. See ' Bot. Centralbl.,' i. (1880) p. 692. 



