Diaptomus. 
325 
Thus the decline of temperature for the month occurred in the 
last three days. In 1896 the temperatures at the opening and. 
close of the month were much the same as in the preceding year, 
but the decline was pretty equably distributed. 
1896. 
Sept 1, 
9:30 a. m. 
Sept. 17, 
4 p. m. 
Sept. 28, 
Noon. 
0 mot,firs.. .. 
21.2° 
18.4° 
16.0° 
10 meters. 
20.2 
18.2 
15.75 
18 meters... 
15.3 
16.1 
15.6 
It therefore appears that the long continued 
warmth 
Of 1895 
gave Diaptomus a chance for an additional brood which did not 
appear in 1894 or 1896. Food, of course, is always present in 
superabundance during September. 
Table IX. — Diaptomus. The. autumnal numbers stated in thousands 
per square meter of surface. 
1894. 
1895. 
1896. 
RflptfimVifir 1—15 
224.6 
125.9 
September 16-30. 
54.6 
331.5 
163.4 
October 1-15. 
67.5 
148.4 
52.8 
October 16-31.... 
38.3 
79.7 
48.8 
November 1-15. 
44.0 
55.8 
29.8 
November 16-30. 
46.0 
28.5 
December 1-15. 
23.9 
33.6 
29.3 
December 16-31. 
(16.7) 
58.0 
24.7 
The winter numbers are seen to be reached early in the season 
— at latest in the first part of November. The winter numbers 
are also seen to be not very different in the three years in ques¬ 
tion and are strikingly independent of the condition earlier in 
the season, The number in September, 1895, was nearly six 
times as great as in the preceding year, while in December the 
difference was less than 50 per cent, in favor of 1895. 
The maximum catches of Diaptomus were 460,000 June 12, 
1895; 651,000 May 18; and 741,000 June 10, 1896. The females 
carry 20-30 eggs in a single sac, during the spriag. In sum¬ 
mer the number declines to 9-15. 
