205 
The larvae were, indeed. counted only about a month after they had 
been transferred from the egg-patches to the food, and being very 
small, some might have been overlooked. 
To verify this method of spreading, the egg-patches, in four 
other trials, were deposited in empty dishes (not provided with 
food), and the newly hatched larvae counted and removed. Any 
overlooking of the larvae was precluded in this manner. The result 
of these four experiments was as follows. 
Eggs Larvae Not hatched eggs. 
NP. ool 
deposited. | obtained. Total. in %/, 
1 15 | 65 | 10 13.3 0/0 
2 ac all BIOS (Zilte 
3 | 191 136 55 28.7 „ 
4 108 Tous Men 305 „ 
Totals and mean 491 381 110 22.4 0/0 
Here, too, there is little if any agreement among the mortality 
figures: The result of these experiments gave no occasion for giving 
up as unreliable the previous method of carefully spreading the 
bran in small quantities. This is why this proceeding has always 
been followed in the subsequent fixing of the mortality figures; also 
because one acquires such a dexterity in it that an overlooking of 
the larvae becomes all but impossible. 
In the first two years the mortality of the eggs of nearly all cul- 
tures was determined. The following averages were then obtained. 
Eggs Larvae Mortality of eggs. 
Year of experiment. f a eA 
deposited. | obtained. | Tota). in 0/6 
1915— 1916 16451 11986 4465 | 27! % 
1916—1917 66517 38861 21656 | 415 , 
Totals and averages in 82968 50847 | 32121 38.7 0/, 
the 2 years. 
The abnormally high mortality figure of the experimental year 
1916—1917 as compared with 1915—1916, is striking. For this no 
definite cause can be assigned, except perhaps temperature intluences, 
