56 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



places, made it evident that tUey were of about the same age, and indi- 

 cated the fact that in waters that are frozen over throughout the win- 

 ter the young white-fish escape from the egg about the first week of 

 April. 



The temperature of Lake Michigan, Huron, or Superior probably 

 does not descend below about 40° or 43° in ordinary winters, and the 

 young fish would be likely to make their appearance a week or two 

 earlier. 



The young fish lived in the glass Jar of water two days, were then 

 transferred to an eight-ounce bottle, and, carried over thirty hours by rail 

 and steamer, and did not arrive at their destination, Waukegan, 111., 

 until thirty-six hours after tbey left Ecorse, Mich. They were all in 

 good condition, and were placed in a quart jar of fresh water. There 

 were thirteen of them altogether. 



A2)ril 19. — The young white-fish are very vigorous, and are in con- 

 tinual motion. The water has been changed once. Although the yelk 

 sac has not diminished, th?y act as if seeking food in their movements 

 around the jar. They open their mouths very wide. Occasionally 

 they take in dust masses, and eject them again as if they were unpal- 

 atable. 



April Ul. — Umbilical sac in one individual diminishing. 



April 22. — Umbilical sacs reducing rapidly. 



April 23. — Yelk-sacs being rapidly absorbed. The membrane on the 

 anterior part of dorsal line is also slightly diminislied. 



April 24. — The umbilical sacs becoming minute. The lin-membraue 

 anterior to position of dorsal becoming absorbed. At the center of the 

 anterior ventral section of fin-membrane, a slightly opaque white spot 

 is apparent. In front of the anus, and on lower half of caudal, are 

 similar ones. The color of the head is assuming a greenish tinge. 



April 25. — The globule in anterior part of yelk-sac has become divided 

 up into numerous smaller globules, scattered like beads, or more like a 

 row of bubbles, through the length of the sac. When they open their 

 mouths the gill-arches show quite distinctly. Excrement voided by 

 some of them. 



April 28. — Umbilical sac entirely absorbed. First dorsal fin becoming 

 well defined. Posterior section of dorsal membrane contracting. Fur- 

 cation of caudal slightly indicated. 



After an absence from home of six days, I returned on May 6 to find 

 only one alive. A brown confervoid growth had developed in the 

 water, and the young fish, attempting to swallow it, always got it entan- 

 gled in its gills, and soon died. 



In my absence I visited Clarkston and purchased for private parties 

 from Mr. N. W. Clark one thousand young trout, which I brought safely 

 to a brook two miles north of Waukegan, III. Mr. Clark gave me one 

 hundred and fifty young white-fish, most of them with the yelk-sac only 

 partially absorbed. The difference in temperature evidently made some 



