204 
When from a culture a sufficient number of eggs had been 
gathered the egg-patches were still kept in the incubator 20 days 
after the last gathering. One is quite certain then that all the eggs 
capable of development have been hatched. The egg-patches are 
removed, some fresh food added in the larvae jar and this is left 
to itself in the incubator for some time. 
Like the pupae, the eggs were gathered only once a week. 
When a large number of beetles is kept together in one box, the 
harvest of eggs is often too small.in proportion to the number of 
beetles. If those same beetles are distributed over a series of small 
pots, the harvest of eggs increases considerably. 
This fact is illustrated by the following case. 
In a box of 21 «10 cm. were 88 beetles; from these were 
obtained respectively 131—148—181 and 121 eggs in the last 4 
gatherings. After distributing these 88 beetles over 8 little pots, the 
next harvest of eggs increased to 468, the 22¢ to 560 eggs, i.e. 
more than four times the last harvest of the preceding series. 
7. Mortality. 
The mortality among the eggs, larvae and pupae is as a rule 
considerable; low mortality figures are exceptions. 
a. Among the eggs. In the 6 nutrition experiments mentioned on 
page 195 there were in each jar an equal number of eggs (viz. 300), 
all of the same origin. The difference between this figure and the 
number of young larvae (living + dead) which were counted at a 
definite point of time, denotes the number of not-hatehed eggs. 
To each 100 eggs laid out, the mortality in those 6 cultures 
amounted. 
Hor Nes ato 6 27, 
eee et Se 55 
se. Gn eels, 
oe ORNE ss, 
” ” Hy) +) 24.6 > 
On an average 28.2 °/, 
The figures diverge rather much, whereas a special cause cannot 
be pointed out. At first arose the thought of errors in the counting 
which was carried out by spreading the bran very carefully, bit 
by bit. 
