ATKINS THE SALMON AND ITS ARTIFICIAL CULTURE. 239 



and perfect health. The males yielded an abundance of health^^ milt. 

 After being stripped the salmon were placed in the small pond in the 

 brook, near its mouth. While here the exhibitions of the sexual in- 

 stinct were ver}" marked. Lying in a current, the females would go 

 through all the manoeuvers of depositing the egg^, though they had 

 already been deprived of all that we could press out. I have repeatedly 

 observed the presence of eggs in the ovaries of fish of the salmon family 

 months after the lapse of the ordinary spawning season. I should attrib- 

 ute the action of these spawned females to a reproductive impulse of a 

 more general nature. The males were at this time very attentive to the 

 other sex, and Mr. Dresser, our foreman, distinctly witnessed the emis- 

 sion of a cloud of milt by one of them while near a female. 



The mode of fecundation employed was an imitation of what is known 

 as the Russian, or dry method, the distinctive feature of which is the 

 exclusion of water from the eggs until the moment of the application of 

 the milt. Vrasski, the originator of this method,* was accustomed to 



* The experiments and observations of Vladimir Pavlovitche Vrasski were made at 

 an establishment founded by him in 1860, in the government of Novgorod, district of 

 Demiansk. In 1H56 his observations led him to conclusions thus detailed in the bulle- 

 tin of the Society d'acclimation, Paris, August, 1871 : 



!•=. Etant regus dans de I'eau an moment oil ils sortent du poisson les ojufs la re- 

 sorbent, et ne gardeut le faculty d'etre f^coud6, que tant que cette resorption n'est pas 

 fiuie, c'est-a-dire pendent une demi-heure au plus. Une fois remplis d'eau, les ojufs ne 

 recoivent plus les spermatozoides. 



2". Les spermatozoides de la laitauce, en tombant dans I'eau, commencent immediate- 

 ment a. faire avec beaucoup de vigueur et de rapidite, des mouvements qui ne cej)eu- 

 dent qu'une minute et demi ou deux au plus; ce laps 'ecoule, on ne voit plus que dans 

 quelques rares spermatozoides des mouvements itarticuliers et convulsifs de Tagouie. 

 Quaud, au sortir du male, on regoit la laitauce dans un vase sec, elle ne change ^las 

 pendent plusicurs heures, et dans cet iutervalle les spermatozoides ue j)erdent pas la 

 faculttS de se mettre a bouger des qu'ils se trouve en contact avec de I'eau. Enfermd 

 dans uu tube sec, et bieu bouch^, la laitauce conserva sa vertue fecoudante pendant six 

 jours. Consid^rant ces observations ainsi bien que les oeufs et la laitauce sont obtenus 

 avec lenteur, leur masse enti^re ne pouvant sortir a la fois, M. Vrasski arriva a la con- 

 clusion qu'en les recivant dans de I'eau, la plus grande partie des oeufs se reussisseut a 

 se saturer d'eau, et que les spermatozoides cesseut presque tous de bouger avaut qu'il 

 soit possible au pisciculteur de m61anger les ceufs avec la laitauce delay6e. M. Vrasski 

 adopta done le systerae des vases sees, et versa sur les oeufs la laitauce ausitot qu'il 

 venait de I'dteudre d'eau. Le succes fut complet ; les ceufs se fecoud^rent tous sans 

 en excepter un seul. 



[Translation.] 



1st. If the eggs are received in water as soon as they come from the fish, they absorb 

 it, and preserve the capacity of fecundation only while this absorption is unfinished — 

 that is to say, for half au hour at the longest. Once tilled with water, the eggs no 

 longer take iu the spermatozoids. 



2d. The spermatozoids of the milt, on falling into the water, immediately begin a 

 series of rapid and vigorous movements that continue only for a miuute and a half, or 

 two at most ; after that, nothing is to be seen except, in here and there a sperniatozoid, 

 disconnected, spasmodic movements. When the milt is taken from the male directly 

 into a dry dish it does not change for several hours, and during this time the sperma- 



