REPORT OF COMMISSIONER OP FISH AND FISHERIES. 39 



season a small number of herring eggs were secured and impregnated, 

 these producing a small percentage of fiy. 



On February 11, 1801, liOO,000 lake trout eggs were received from the 

 North ville Station, and produced 192,000 fry, which were liberated about 

 the end of March, at j)oints in the lake in the vicinity of the station. 



The collection of pike perch eggs was begun April 14, 1891, they too 

 being taken by the fishermen; 149,000,000 eggs were obtained, of which 

 58,000,000 were sent to the Erie hatchery of the Pennsylvania Fish Com- 

 mission. In the collection of these Mr. William Buller, superintendent 

 of the Erie hatchery, rendered active assistance. The eggs held at the 

 station produced 60,000,000 fry, which were liberated in the lake prior 

 to May 20, 1891, the season's operations in fish-culture terminating M'ith 

 their release. Experiments were made with the pike lierch eggs looking 

 to the separation of those that mass in lumps. The method pursued con- 

 sisted in detaching the lumps from the eggs already free, by means of 

 a screen. The lumps Avere then rubbed between the palms of the hands, 

 separating the eggs. It was found that eggs so treated hatched with 

 no greater loss than those naturally free. Attempts to hatch the eggs 

 when in lumps, however, resulted in almost total loss. 



NORTHVILLE STATION, MICHIGAN (FRANK N. CLAKK, SuPKltlNTENDENT). 



1889-90. 



Whitejish. — The collection of whitefish eggs for this station was lim- 

 ited to Lake Erie, 10,000,000 being derived from the vicinity of Monroe 

 and 25,000,000 from Sandusky. These were carefully prepared for ship- 

 ment and distributed to other hatcheries for hatching. The disposition 

 of the good eggs, 28,400,000, is given in the details of distribution. 



The success heretofore attending the partial trial of graveled troughs, 

 as practiced during the three preceding seasons in developing trout 

 eggs, led to the adaptation of the method to all the trout eggs handled 

 at the station, and with results highly gratifying. Tliis consisted in 

 spreading as evenly as possible 10,000 to 12,000 eggs over a space of 

 gravel bottom 12 1)y 15 inches. The eggs Aver(i allowed to remain on 

 the gravel until the eye spots were clearly developed (a period of about 

 forty days), being then taken up and placed on Avire trays for hatching. 



Von Belir trout. — The readiness with which the Von Behr trout has 

 become acclimated, together with its hardiness and rapid growth, has 

 greatly encouraged its further propagation. From the brood stock 

 ir»;^,400 eggs were obtained, of which 58,000 were transferred and 75,000 

 held for hatching at the station. The spawning season began October 

 21, 1889, and continued seventy-three days. From 75 females, 3 and 4 

 years old, the production of eggs was 85,700, and from 239 females, 2 

 years old, 77,700. Of this species brought over from tlie previous 

 season, there were 0,175 yearlings delivered for distribution. 



