REPORT OF COMMISSIONER OF FISH AND FISHERIES. 55 
Washington, D. C., the Potomac River, creeks in Virginia accessible 
to the station by wagon, and from Fort Washington Station, Md. 
Spawning was observed in the fresh-water aquaria as follows: Yellow 
perch, fifteen deposits of eggs from December to April, inclusive; three 
mussels in March and April; rainbow and tessellated darters in April. 
Yearling rainbow trout were held through the month of May in a tem- 
perature of 72° to 76° F. 
In the salt water a rainbow trout spawned in March, 1890, after hav- 
ing deposited eggs a month previous in fresh water; several nests were 
built by the two-spined sticklebacks in April and May; several common 
killifish spawned in April; and in June king crab eggs were received 
and hatched. From unknown causes mollusea, hermit-crabs, anemones, 
starfish, and sea-urchins could not be successfully kept. 
Colored and plain sketches were made by Mr.S. IF. Denton illustrat- 
ing the spawning habits of mussels and of rainbow and tessellated 
darters. 
1890-91. 
Two collecting trips ‘were made down the Chesapeake Bay, and 
specimens were also obtained from Woods Holl Station, Cold Spring 
Harbor, and from other sources through the distribution cars. Young 
Shad, 3 to 4 inches long, received from the fish ponds, Washington, 
D. C., in October, 1890, were with partial success held in the salt-water 
aquaria. Atlantic and quinnat salmon, and rainbow, brook, and lake 
trout yearlings were successfully kept in the salt water. About No- 
vember 1, 1890, a large female skate was received and placed in a salt- 
water tank; in January several eggs were deposited, which, on May 
12, were found to contain living embryos. Both the common newt and 
top-minnow reproduced in April in fres’ water. 
In December, 1890, the salt-water temperature fell to 48° F'., when 
artificial heat was introduced into the tank room, which maintained a 
temperature of 50° to 54° during the remainder of the winter. In June 
the temperature went up to 80°. 
STEAMER F isn Hawk (Lieut. Rosperr Pratt, U. 8S. N., COMMANDING). 
1889-90. 
After the establishment of the shore station at Gloucester City the 
Fish Hawk, as in previous years, entered upon the propagation of shad 
on the Delaware River. The vessel was anchored off Gloucester, the 
water supply used in hatching operations being taken directly from the 
river. The crew began taking eggs April 30, using the launch Petrel. 
The river temperature was 57° F. By May 15 the water had risen to 
63°, when the collections of eggs amounted to 27,234,000. On May 2 
they amounted to 33,915,000, when the work closed, the temperature 
being 64°. There were produced 20,596,000 fry, which were liberated 
