9 
Making in all 1,028 eges found in the stomachs of four 
birds. Four birds killed later in the season had eaten the 
female imagoes of the spring cankerworm, as follows: — 
Moths. 
No. 1, 41 
No, 2, 18 
No. 3, 27 
No. 4 19 
“ 
Making a total of 105. In Nos. 2, 3 and 4 of the last table 
there were large numbers of eggs also. It is safe to say 
that there were 150 eggs in each stomach, in addition to the 
female moths eaten. 
Mr. Bailey carefully counted the eggs in the ovaries of 
twenty of these female moths, with the following results: — 
No. 1, los) No. 1. : ‘ ee 
No. 2, one | No; 12, >. : ; 7 Oo 
No; 3; PaTieNo,. 135. - ? : 2 193 
No. 4, 184 | No. 14, . ' : .~ dot 
No: 5, 213 | No, 15, . : : . 281 
No. 6, tor | No. 16; 4 ; ' . 242 
Ne. F 140 | No. 17, . : ‘ ~- LUG 
No. §&, 220 | No. 18, : : . 281 
No. 9, 200 | No. 19, ; F : . 102 
No. 10, 130 No. 20;, . ‘ : . ee 
It will be seen from this table that the average number 
of eggs found in each moth is 185. Mr. Bailey is very posi- 
tive, from his continuous field observations, that each chicka- 
dee will devour on the average 30 female cankerworm moths 
per day from the 20th of March until the 15th of April, 
provided these insects are plentiful. If the average number 
of eggs laid by each female is 185, one chickadee would thus 
destroy in one day 5,550 eggs; and in the twenty-five days 
in which the cankerworm moths “run” or crawl up the 
trees, 138,750. It may be thought that this computation 
is excessive, and it is probable that some of the moths were 
not captured until they had laid some of their eggs, but the 
chickadees eat these eggs also. When we consider further 
