164" INTERNAL ANATOMY OF INSECTS. 
for their artificial mechanism can be compared with this. 
Each cartilage inosculates very closely in the adjoining 
one, and all are besides bound together by a strong skin 3 . 
The manner in which the eggs of insects axejecundated 
by the male sperm is one of those mysteries of Nature 
that are not yet fully elucidated and understood. We 
can readily conceive that all the eggs may be fertilized 
by a single intercourse in the case of insects which, like 
the Ephemera; and Trichqptera, exclude the whole mass 
at once ; or like many moths and butterflies, in a very 
short time afterwards ; but the subject becomes much 
more difficult to explain when we advert to the female 
of the hive-bee, the whole number of whose eggs, de- 
posited in two years, are, as Huber has demonstrated, 
in like manner fertilized by a single act b : — if you bear 
in mind, however, what I have lately observed with re- 
gard to Malpighi's discovery of a sperm-reservoir in 
insects, you will more readily comprehend how in this 
case a. gradual fecundation may take place. The princi- 
pal objection to this solution of the difficulty in the case 
before us, is derived from the very small size of the organ 
supposed to be destined for this purpose — it being 
scarcely bigger than the head of a pin c : it seems there- 
fore incredible that it should retain any portion of an 
extraneous fluid at the end of twelve or eighteen months, 
and still more unlikely that the fluid should in the in- 
terval have sufficed for the slightest moistening of not 
fewer than 30,000 or 40,000 eggs. The only hypothesis 
that seems at all to square with this fact, is that of Dr. 
Haighton, — that impregnation is the result not of any 
3 Arachnid. 40. b Huber KoitvcL Obserw i. 106. 
c Swamm. Bill, Nat, t. xix./. ?. 
