THE HATCHING OF THE COD EGGS. 



219 



where they were visited and impregnated by the males, ami left to become the food of the various 

 animals so abundant in such localities. They had at times noticed the little transparent globular 

 bodies in the water, but it had never occurred to them that they were the eggs of any fish. 



"There are many ways in which the eggs may be destroyed. The principal loss is probably 

 the result of non-impregnation, for unless they come in contact with the milt of the male very soon 

 after being thrown from the parent they lose .their vitality. Again, being drifted about by the winds 

 and tides, they are often carried long distances from the spawning grounds into the little bays and 

 coves, and are driven in immense numbers upon the shores, or are left dry by the tides, where they 

 soon die from exposure to the atmosphere, or, during the cold winter weather, are instantly destroyed 

 by freezing. Ipswich Bay, the most extensive spawning ground in the locality, is especially 

 unfortunate in this particular, for the heavy storms from the north and east sweep with unbroken 

 force across its surface, and each breaker as it rolls in upon the beach must carry with it many 

 millions of eggs. 



"But such impregnated eggs as escape destruction upon the shores are subjected to the ravages 

 of the myriads of hungry animals living about the rocks and coves. One day in January we placed 

 a jelly-fish or medusid, having a diameter of but one and a half inches, into a tray of eggs in 

 the hatching-room, and in less than five minutes it had fastened seventy eggs to his tentacles, 

 loading some of them so heavily that they were severed from the body by the weight or resistance 

 of the eggs as they were dragged through the water. 



"By the aid of a microscope, numbers of vorticelli were frequently found upon the eggs, in one 

 case forty-six being counted on a single egg. In addition a peculiar growth, thought to be minute 

 algoe, was often noticed upon them. Just what influence these would exert, or whether they would 

 occur in the clear water outside the harbor, is not known. Thus, owing to the many different 

 circumstances that tend to destroy the eggs, probably but a very small number out of a million 

 are successfully hatched, and of the young fish but few reach maturity." 



In the winters of 1878-'79 and 18SO-'81 the United States Fish Commission successfully carried 

 on the work of artificial propagation of Codfish. The results of the first winter's work at Gloucester 

 will be found detailed in Mr. Earll's paper, from which quotations have already been so extensively 

 taken. 



In addition to his other observations, Mr. Earll computed the number of eggs in Codfish of 

 different sizes. The results of his observations are shown in the following table: 



Table showing the number of eggs in Codfish of different sizes. 



1 No. 1 (a) ivprrscijts :i second quantity taken from the same ovary the following day, and the greater number 

 may bo partially accounted for by the evaporation of moisture during the night. 

 * No. 2 contained a few ripe eggs. 



