HABITS OF THE BLACK CRAPPIRE. 13 
female; July 8, 2 ripe males, 5 spent females; July 15, 5 ripe males, 
5 spent females. ; 
The observations show that, in Lake Wingra, the most active 
spawning period came later in the season than at Havana, Ill., which 
is more than 200 miles farther south. It is also apparent that, in the 
present observations, spawning took place at somewhat higher tem- 
perature than those reported by Richardson (1913). Compared to 
the perch, the crappie breeds in warmer water. Perch begin spawn- 
ing when the temperature is 8 to 9° C.; crappies when it is 19 to 20° C. 
No observations were made on eggs or young in Lake Wingra 
until the latter part of July, in part on account of the turbidity of 
the water. After that, small crappies were captured at intervals 
until midwinter (Table 2). During the autumn and winter they 
were quite common in the aquatic vegetation alongshore, and after 
the lake froze over they were to be found in the mouths of the small 
streams, where the water was somewhat warmer than in the lake 
itself. In the latter habitat they were associated with other small 
fishes in the following proportions, as judged by catches with a 
dip net: Pomowis sparoides, 384; Pimehales notatus, 27; E'ucalia in- 
constans, 13; Lepomis incisor, 11; Fundulus diaphanus menona, 11; 
Labidesthes sicculus, 5; Micropterus salmoides, 2; Ameriurus nubu- 
losus. In the mouth of the particular stream where observations 
were made crappies were the most abundant fishes. 
IV. MIGRATIONS. 
Judging from the catches in gill nets and on hooks*® the crappies 
are active in Lake Wingra from the middle of February until the 
middle of October. In autumn, after the water temperature had 
fallen to about 10° C., they were no longer captured by either method 
of fishing in places where they had been more or less common 
throughout the warmer months. This may have been because the 
crappies did not move about, because they collected in one or more 
schools which did not happen to be encountered, or because they 
remained in places where no fishing was done. 
Twice during the winter (Dec. 30 and Jan. 20) an adult crappie 
was seen in the shallow mouth of a stream (7.5° C.) at the north- 
west corner of the lake. These were the only adult individuals 
observed in Lake Wingra from October 14, 1916, to February 10, 
1917, though fishing was carried on each week. When crappies began 
to bite in the spring, they were caught in only one locality for the 
first two weeks—over a hole about 30 feet deep, where a hydraulic 
dredge had worked during the preceding summer. Despite the 
occasional individuals observed in shallow water, the evidence ap- 
pears to indicate that the majority of the crappies descend into the 
deepest regions of the lake in the autumn, and that they remain 
there in comparative inactivity throughout the winter. In the 
spring they return to shallower water, where they remain during the 
summer. 
Apparently crappies often swim in small schools during the sum- 
mer, particularly just before the spawning season. June 10, 1916, 
between 5 and 7.15 a. m., on the south shore of Lake Wingra, a man, 
‘@ For details of these catches, see Tables V and XXXII in a paper by Pearse and Ach- 
tenberg soon to be published by this Bureau. 
