1882.J 



MICROSCOPICAL JOURNAL. 



137 



The Salmon Disease. — Prof. 

 Huxley contributed an important 

 paper to the Royal Society a few 

 months ago, on The Salmon Disease. 

 In certain rivers the fishes are affect- 

 ed by an epidemic disease, which 

 manifests itself in white patches up- 

 on the fish where there are no scales. 

 As the fungus grows, a sore forms 

 which may extend to the bone. 



The fungus is a Saprolegnea pro- 

 bably S. ferax, but of this there is 

 no proof. The zoospores from this 

 fungus were never observed ciliated 

 and motile ; but they are exceedingly 

 minute, and become rapidly dissemi- 

 nated. They are produced in great 

 numbers — a single fly infected with 

 the fungus may bear i,ooo fruiting 

 hyphae, which, in one day may pro- 

 duce 40,000 zoospores. 



The hyphae seem to not only 

 traverse the epidermis of the fish, but 

 also to bore through the superficial 

 layers of the derma. The epidermis 

 is entirely destroyed. 



The only method of preventing 

 the spread of this fungus among 

 salmon, is to remove every infected 

 fish from the stream, though it may 

 not be worth while to adopt this 

 method in practice. Although sea- 

 water kills the fungus when it comes' 

 in contact with it, if the latter has 

 penetrated the derma the fish may 

 go to the sea and recover from its 

 attack, but on returning to fresh- 

 water, the disease may break out 

 again from the hyphse in the derma. 



NOTES. 



— The local committee having charge of 

 the arrangements for the meeting of the 

 •American Society of Microscopists to be 

 held in Elmira, beginning August 15th, 

 have been appointed, and are busy in pre- 

 paring for the meeting. 



Mr. C. N. Shipman is Chairman of the 

 Reception Committee. The Secretary of 

 the local society is Dr. T. S. Up de Graff. 



— The bacillus of leprosy, which has 

 been described by several authors, but 

 concerning the existence of which there is 

 some dispute, has. been found by Dr. I. 



Hermann, of Baltimore, who describes his 

 method of examination in an article which 

 s illustrated by a cut — published inAr- 

 c hives of Medicine. 



The author believes that others have 

 failed to find the Bacillus leprce because 

 they have not adopted the proper meth- 

 ods of staining the leprous tissues. The 

 article should be read by those who are 

 engaged in the study of bacteria in tissues. 



— Mr. Vorce informs us that the new 

 Bausch and Lomb \ and ^-inch objectives, 

 which, it is claimed will resolve 152,000 

 lines to the inch, " easily resolves the bal- 

 sam Amphipleiira pellucida with mirror 

 exactly central, using sunlight and no con- 

 denser." He says, " the resolution is got 

 instantaneously, as easily and as quickly 

 as X-inch resolves Navicula lyra." 



— A very interesting article on " The 

 Structure and Division of the Vegetable 

 Cell " was published in the March num- 

 ber of the "Journal of Quekett. Microsco- 

 pical Club," by W. H. Gilbert, F. R. M. S. 

 There is a plate illustrating the process of 

 division. It is a most excellent article for 

 botanists to study. 



CORRESPONDENCE. 



To THE Editor: 



I wish to enquire through the columns 

 of your Journal, if the " stephanoceros" 

 is plentifully found in this country.-* If 

 any of your readers can inform me through 

 the columns of your JOURNAL, they will 

 greatly oblige 



H. H. Davison. 



To THE Editor: — Will you have the 

 kindness to inform me what are the best 

 media for mounting plant-hairs and 

 glands ; also micro-fungi, stating best 

 method of preparing these objects for 

 mounting.'* Many of the micro-fungi are 

 upon leaves. 



E. P. 



[Plant-hairs may sometimes be mount- 

 ed in balsam, especially those which are 

 displayed well with the polariscope ; but 

 in most cases glycerin-jelly will be found 

 more suitable. The-leaf glands are usu- 

 ally best seen when the specimens are 

 stained and mounted in balsam. The 

 minute fungi on leaves will probably be 

 seen best in opaque specimens, mounted 

 dry. 



We can hardly give satisfactory- directions 

 for preparing the specimens in this place. 



