XLIV EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



eggs tliat can be secured, in view of the fact that a mature cod will fur- 

 nish from two to nine millions, and the number of spawners taken in the 

 vicinity of Cape Ann almost every day being very great. Of course it 

 requires special conveniences to do this work, particularly during the 

 inclement season of winter. The season during which the eggs can be 

 obtained, however, is a very long one, extending from November to 

 March and April. 



For a detailed account of the whole experiment and of the observations 

 made during its progress, I refer to the article by Mr. E. E. Earll, in the 

 appendix. This may justly be claimed as perhaps the most important 

 contribution ever made to our stock of information respecting the 

 natural history of our principal food-fish. 



In connection with the work upon the codfish, satisfactory experi- 

 ments were also made in regard to hatching the sea herring, as detailed 

 elsewhere. 



The Sole (Solca vidgaris). 



Eeference has been made heretofore to a wish to meet the oft-expressed 

 desire of citiz<^ns of the United States that the European sole might be 

 introduced into American waters; and not daunted by the essential non- 

 success of the work of last year (by which only two were successfully 

 transi)orted to our shores), arrangements were made with Mr. C. L. Jack- 

 son and Mr. Long, of the aquarium at Southport, in England, to secure 

 a supply of young fish and hold them in readiness for further action. 

 In accordance with this, over eleven hundred were brought in during 

 the season. Many deaths occurred in this number in a few days after 

 being captured, but 165 surviving were kept alive in the tanks for a 

 considerable period of time. 



Mr. Mather, of whose visit to Europe in connection with the transpor- 

 tation of the eggs of the California salmon mention has been made on 

 another page, went to Southport, on his return to the United States, 

 and took charge of the fish. Unfortunately, however, the necessarily 

 crowded quarters, and, possibly, the fact that they were brought in tin 

 cans, which rusted very rapidly, proved adverse to a successful experi. 

 ment, and the entire lot died, one after another, before the return voyage 

 was completed. 



A portion of this ill success was thought by Mr. Mather to be due to 

 a pump in use for aerating the water, the packing of which had been 

 saturated with some chemical substance which exerted a deleterious 

 influence. In this, as well as in the previous experiment, the United 

 States Fish Commission is indebted to the courtesy of the Canard Steam- 

 ship Company for imjiortant facilities. 



The Sponge of commerce. 



Among the more recent enterprises in the way of artificial propagation 

 of aquatic animals is that relating to the artificial propagation of the 

 sponge of commerce. Prof. Oscar Schmidt, of the University of Gratz, 



