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 a . 

 The manner in which the eggs of insects arefecundated 

 by the male sperm is one of those mysteries of Nature 

 that are not yet fully elucidated and understood. We 

 can readily conceive tttat all the eggs may be fertilized 

 by a single intercourse in the case of insects which, like 

 the Ephemerce and Trichoptera, 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 n 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 Nouvel. Observ. i. 106. 



c Swamm. tiibt. Nat, t. xix./. 2. 



