ATKINS THE SALMON AND ITS AETIFICIAL CULTURE. 239 



aiul perfect health. The males yielded an abundaiiee of healthy 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 very marked. Lying in a current, the females would go 

 througli all the maneuvers of depositing the eggs, 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 

 mouths after the lapse of the ordinary spawning season. 1 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 expeiiruents and observations of Vladimir Pavlovitche Vrasski were niado at 

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

 Demiansk. In 1856 his observations led him to conchisious thus detailed in the bulle- 

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



1<'. I5tant regus dans de I'eau au moment oil ils sortent du poisson les ceufs la re- 

 sorbeut, et ne gardent le faculte d'etre feconde, que taut que cette resorption n'est nas 

 finie, c'est-a-dire pendent nne derai-heure au plus. Uue fois remplis d'eau, les ojufs ue 

 recoivent plus les spermatozoides. 



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

 ment a faire avec beaucoup de vigueur et de rapidite, des mouvements qui ne cepen- 

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

 quelques rares spermatozoides des mouvements particuliers et convulsifs de Fagonie. 

 Quand, au sortir du male, on regoit la laitance dans un vase sec, elle ne change pas 

 pendent plusieurs heures, et daus cet iutervalle les spermatozoides ne perdeut pas la 

 faculte de se mettre h bouger des qu'ils se trouve en contact avec de I'eau. Euferm6 

 dans un tube sec, et bieu bouche, la laitance couserva sa vertue fecondante pendant six 

 jours. Considerant ces observations ainsi bieu que les ojufs et la laitance sont obtenus 

 avec lenteur, leur masse eutiere ne pouvaut sortir a la fois, M. Vrasski arriva a la con- 

 clusion qu'en les recivaut dans de I'eau, la plus grande partie des ceufs se reussissent a 

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

 suit possible au pisciculteur de m^lauger les ceufs avec la laitaiice delayee. M. Vrasski 

 adopta done le systeme des vases sees, et versa sur les ceufs la laitance ausitot qu'il 

 venait de I'etendre d'eau. Le succes ftlt complet ; les ceufs se fecond^reut 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 an hour at the longest. Once filled with water, the eggs no 

 longer take in the spermatozoids. 



2d. The spermatozoids of the unit, on falling iiito the water, immediately begin a 

 series of rapid and vigorous movements that continue only for a minute 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 spernia- 



