208 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



eggs. lie also accompanied the crews for examination of waters with his microscopes 

 and an assistant and a botanist, and made quite extensive examinations of the fish 

 food and aquatic plants, and incidentally of some fish- parasites. He also prepared a 

 still more elaborate article on the development of the embryo of the wall-eyed pike, 

 covering about 80 pages, which, with the plates illustrating it, are published with the 

 tenth report. He is at present inaugurating some experiments connected with the 

 food of the whitefish and its life and abundance and when and how distributed, which 

 it is hoped will be of value in determining the proper places for planting the whitefish 

 fry. It is designed to make this examination as careful and exhaustive as the means 

 at hand will allow, and it is planned to interest the authorities of the University 

 of Michigan to cooperate with the commission in extending work of this scientific 

 nature from time to time. No work of the commission has attracted wider attention 

 among intelligent readers than the work already done by Prof. Reighard. 



A boiler and pump were added to the Detroit hatchery for use in case of an emer- 

 gency causing the stoppage of the flow of the city water, such as had been once or 

 twice experienced. By this means the water in the storage tanks could on short 

 notice be pumped up into the troughs which feed the hatching jars and keep the 

 water circulating through the eggs until the stoppage of the regular flow of the city 

 water ceased. The storage-tank capacity of the hatching-house was also nearly 

 doubled by enlarging the wing of the building. 



In the summer and fall of 1880 the efficiency of the Detroit whitefish hatchery was 

 doubled by the erection of two additional frames of jars, which increased the number 

 of jars in place to 1,050, with a hatching capacity of nearly 200,000,000; but the diffi- 

 culty of obtaining sufficient ova to fill the jars prevented for a year or two reaping the 

 full benefit of the increased capacity. The whitefish plant in 1880 was 03,000,000, and 

 in 1800 it was 100,750,000. The wall-eyed pike plant of 1889 was 44,340,000, and in 

 1890 it was 22,300,000. The brook-trout plant of 1889 was 2,408,000, and in 1890 it was 

 2,578,000. The appropriations by this time had increased to upward of $20,000 a year, 

 and the inventory of the property of the commission showed a valuation of upward of 

 $35,000. 



The tenth report covers the years 1891 and 1892, and is a substantial volume of 

 228 pages. In the fall of 1891 a small hatchery for whitefish, lake trout, and brook 

 trout was established at Sault Ste. Marie, containing 200 jars, besides such hatching 

 troughs as the space in the building would admit. The city paid the rent of a small 

 store building in which this hatchery was set up, and furnished city water free. This 

 hatchery was run during the seasons of 1891 and 1892, but, owing to difficulty and 

 disappointment in procuring whitefish ova., was not filled until 1892. The purpose of 

 a whitefish hatchery on Lake Superior was to provide for stocking that great lake, the 

 hatch at the Detroit house coming on too early to be planted, on account of the ice 

 in t he harbors. It was thought that the difference in the temperature of Lake Superior 

 water would retard the hatch about two or three weeks, which proved to be the fact. 

 The water at the Sault proved admirably adapted to the work of hatching both white- 

 fish and brook trout. The temperature of the water is remarkably even and cold. It 

 began November 15 at 42°, and for the month ensuing varied from 42° to 38°, and 

 about January 1 ran down to 34°, where it remained without over 1° variation 

 either way until April 20, and from then until May 15 it did not go above 40°. A daily 

 record of the temperature of the water is kept at each station while in operation. 



