197 
On the 10 of February 1916 the larvae of N°. 1 (B) and N°. 
3 (M) were sieved, and each group was divided into two halves of 
an equal number of larvae. The same process was applied to N°. 2 
(B.P.) on April 20, 1916. 
The 6 groups of larvae were put in separate jars. To 3 of these 
(half of each group) rusk was added; the 3 other jars kept the old 
food without rusk. 
On April 20, 1916, ie. 69 days after the above-mentioned 
division, the pupae collected from the sub-groups of N°. 1 were 
counted, and on July 8, 1916, ie. 48 days after the division, the 
pupae of the sub-groups of N°. 3. The group N°. 2 had not yet 
yielded any pupae. The remaining living larvae were weighed on 
a chemical balance. The result of this is shown in the following 
tabular statement. 
Here too, the four conclusions drawn from the first experiment 
(Table I) may be maintained unabated. That the addition of rusk 
to meal is very effective is manifest, not only from the more 
numerous pupation (80°/, more), but also from the absolute weight 
of the remaining larvae, which for M + R is nearly twice as great 
as for M alone. The enormous difference in the mortality of the 
larvae is also remarkable. 
_Until-now the rusks had always been added unbroken. 
A special reason gave occasion to putting the question whether 
rusk would operate as favourably if reduced to dust and mixed 
with the bran. Indeed, from former experiments (not undertaken 
for food purposes) the experience had been made that larvae fed 
exclusively on pulverised rusk (rusk meal), do not grow, and many 
die. The increase of the body weight of the larvae fed on rusk 
alone amounted to 48°/, in 43 days with a mortality of the larvae 
of 38°/,, whereas the figures for the larvae fed on bran appeared 
to be 117°/, with a mortality of only 1.5 °/,. 
The food experiments were therefore continued with the following 
modifications. The 118 larvae which remained on the 20‘ of April 
1916 of experiment N°. 1a. (cf. Table I], column 7), i.e. larvae fed 
exclusively on bran, were again divided into two equal halves, each 
of 59 larvae. With one of these halves the old way of feeding 
(only bran) was kept up, the other half received bran ++ ruskmeal. 
On the 8 of July 1916 the larvae of both groups were removed 
and weighed on a chemical balance. Pupae were not gathered from 
these groups between April 20 and Juli 8. (Table III). 
The result obtained was as follows. 
