25 
gonidea). Most Eumeninae, chiefly potter wasps, suspend their 
egg by a thread to the roof of the cell, which is provisioned 
with more or less active caterpillars. Some of the more special- 
ized wasps of this group (Synagris, Zethus) lay their egg freely 
in the bottom of the cell. Stenogaster and the social wasps build 
cells in a more or less inverted position, and there the egg is glued 
in the bottom of the cell itself. Wasp eggs may hatch in less than 
two days (Dolichurus, Methoca sp., Notogonidea) to four, five or 
more days (7iphia sp.). Cool weather greatly retards the devel- 
opment of the egg, so that two weeks or more may be required to 
hatch it. 
THE Larva. 
The next stage in wasp development is that of the larva. The 
larva is a more or less whitish grub, devoid of legs, but possess- 
ing adequate jaws. In many cases so gradually does the young 
erub break through the very thin and closely -adhering egg- shell 
that it is hardly possible to determine just when the egg hatches; 
in these cases it seems that the grub punctures the eny elope under 
the mouth and feeds at that point and simply outgrows its en- 
velope. Or else the larva may crawl out of the shell (Methoca 
sp. Epyris). The eggs of Eumeninae are reasonably firm, so 
that after hatching, the shell may collapse but little, and since the 
eggs of these wasps are not attached to their food, it follows 
that, in order to feed of themselves, the young grubs must be 
active from the very first, and this is true of those that I have 
seen. In the case of the Sphecidae, Psammocharidae, and others, 
the newly-hatched grub is usually a very helpless creature. \When 
it breaks through the egg-shell it finds food practically in contact 
with its mouth and so may feed at once. But if at this stage 
it be removed to another portion of its victim’s anatomy it very 
frequently perishes. Later on, however, after several moults, 
which are often difficult to follow (except in the Eumeninae), it 
acquires stouter mandibles, and, becoming more able-bodied, 
largely abandons its first method of feeding by suction, for a 
chewing one; thus it reaches out to the different victims or 
portions thereof, to devour the tougher parts—head, legs, etc. 
The soft, footless wasp grubs, one appearing much like another, 
should, if sufficiently studied, present characters that would place 
them in natural groups. There is here a field for the taxonomist. 
The feeding period of the larva is usually brief, perhaps three 
to fourteen days, according to species, food and climatic con- 
ditions. 
