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If the beetles need not be gathered daily, a piece of rusk should 
be laid under the patch. If no food is offered them in time, they 
eat the pupae. 
The pupae dishes were covered with a glass plate reaching beyond 
the rim. In this way they may be piled up in the incubators, while 
any escape of the beetles is precluded. 
6. Gathering the Eggs. 
The collecting of the eggs was a matter of no small importance 
for the obtaining of a large posterity. The difficulties that were 
expected, did not occur; the problem was solved in quite a satis- 
factory manner. The beetles emerged in the pupae dishes are trans- 
ferred to the beetleboxes in which the production of eggs is awaited. 
The beetles were kept in tin boxes with smooth walls and pro- 
vided with a cover closing not too hermetically. The bottom of the 
boxes is covered with a patch of black sateen, in which a few holes 
have been cut to let the beetles through, which hide by preference 
under the patch. On the top of the sateen small pieces of a woolly 
material are scattered. The choice of the quality of this material 
(egg patches) on which the eggs are deposited, is very important. 
On this point the beetles are very particular and will not at all, 
or only in a small number, deposit their eggs if the stuff is not 
woolly or thready enough, so that the ¥ cannot attach the eggs on 
it. If the stuff is too thready, the eggs are laid so deep in the tissue 
that they are difficult to discover. Also Sanine records this peculiar 
habit of the beetles of depositing their eggs on a woolly material. 
The egg patches had a size of about 1 or 1'/,¢.m’. These small 
patches are preferable, for various practical reasons, to those of 
larger dimensions. 
As food for the beetles, pieces of rusk were used, soaked with 
a few drops of milk, or fresh cut pieces of potato. Of the latter the 
_ beetles eat all but nothing; yet they greedily fall to them, probably 
attracted by the humidity of the food. 
The food is put under the sateen, in which the holes serve for 
passages to reach the egg-patches, while the sateen, to some extent, 
prevents the egg-patches from being defiled by the faeces of the 
beetles. The egg-patches are transferred, with the eggs clinging to 
them, into a jar in which beforehand a thin layer of food has been 
brought for the coming young larvae. 
In a temperature of 25° C. the hatching of the eggs takes about 
8 or 10 days. 
