XVII.-A CONTRIBUTION TO THE EMBRYOGRAPHY OF OSSEOUS 

 FISHES, WITH SPECIAL REFERENCE TO THE DEVELOPMENT 

 OF THE COD (GADUS MORRHUA). 



Bv John A. Rydkr. 



1. — Introductory. 



The following paper, as far as it relates to the codfish, is mainly the 

 result of studies carried on at Wood's Holl, Mass., during the month of 

 January, 1881, and at Fulton Market, Xew York, in February, 1882. 

 At Wood's Holl, the writer, as investigator, was associated with Col. 

 M. McDonald and Capt. H. C. Chester, the latter having been previously 

 engaged, together with Mr. R. E. Earll and Mr. F. N. Clark, in an at- 

 tempt to propagate the cod artificially at Gloucester, Mass., in 1880. 

 It is now claimed by the fishermen in the vicinity of Gloucester and 

 Wood's Holl that the results of the work of the U. S. Fish Commission, 

 in placing artificially reared embryos of this species into the waters of 

 these localities, have already shown themselves as shoals of young fish, 

 the presence of which it is not possible to account for on any other the- 

 ory than that they are the survivors of those partially reared by the two 

 parties which have been alluded to above as being .sent out by the U. 

 S. Fish Commissioner. The fullest measure of success, notwithstanding 

 the gratifying result claimed for us by the fishermen, it has not yet been 

 our lot to attain. The mortality of the artificially fertilized ova is still 

 very great under api)arently the best conditions, though this fact 

 need not hinder us in further endeavors to multiply this exceedingly 

 valuable food-fish of our northern coasts. If the annual destruction of 

 ova which accompanies the marketing of the adult fish in New York 

 City alone could in any way be abated, the future of the race of codfish 

 would in a great measure be assured. Inasmuch as a very large pro- 

 portion of the fish brought to New York are alive and preserved for 

 days in large floating cars in the harbor, the artificial fertilization of 

 many hundreds of millions of ova annually would be a matter of no 

 great difficulty. Such a plan has in fact been already proposed by 

 Professor Baird. The ova after fertilization are to be transported in 

 launches some distance from the filthy and too slightly saline water of 

 New York Harbor, and poured into the waters of the open sound or 

 bay. to undergo further development under natural conditions with- 

 out further cnre from the hand of num. This ])lau seems feasible, and 



one wJiich will demand but comparatively small outlay in its execution. 



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