199 
the pupation is 20°/, higher, the mortality of the larvae is equal, 
the weight of the remaining larvae is 38 milligrams per larva more. 
This result could not be expected when at the outset it appeared 
(cf. Table I) that to meal and bran without any addition, meal 
was preferable; the addition of rusk shows the opposite, and this 
with rather strongly telling figures. It is probably only the fat and 
the albumin of the rusk that have operated so favourably. 
Especially fat is only seantily found in bran and meal (+ 1.6°/,), 
whereas the rusk used contained 8.9 °/,. 
Summarizing the results of these nutrition experiments, they may 
be worded thus: 
1. Exclusive meal food is preferable to exclusive bran food. 
2. Rusk as additional food to meal as well as to bran always 
has a very favourable influence on the growth and the quicker 
development (pupation) of the larvae; this holds good for rusk in 
an unbroken or a ground state alike. 
3. The most favourable results (more pupae, and low mortality 
and high weight of the larvae) were obtained by a mixed nutrition 
of bran + rusk. 
4. Ground rusk as exclusive food for larvae is perfectly unsuitable. 
The mortality is considerable, the increase in weight small, the 
pupation is stopped. 
5. The addition of slices of peat to meal or bran has no influence 
on the growth of the larvae, and is worthless as food. Peat seems 
to have a directly or indirectly noxious effect; the mortality is 
abnormally high. 
3. The number of moults. 
In the literature (BkEHM p. 128; Friscu vol. III p. 1; SALING p. 
2/8; Sturm p. 21/22) it is always stated, that the larva moults 
four times, and that after the fourth moult the pupa appears. 
Apparently this statement has never been controlled, for a simple 
experiment would immediately have shown, that it is false. 
A larva was put in each one of a series of numbered small pots 
filled with fit food. The larvae were at most one or two days old, 
and still white in colour. 
At fixed times these pots were searched for moults. The first mone 
are only to be found by carefully. spreading out the food, and 
examining it with a lens. Notwithstanding a close inspection they 
sometimes escape notice, because they are often no longer intact, and 
broken up into smaller fragments, so that they are no longer to be 
recognized as moults. 
