342 PHYSIOLOGY. 



distended uterus, into the superior narrow aperture of which two ramose 

 vessels, which terminate in blind filaments, open themselves, and which, 

 according to Ramdohr *, are secreting vessels that convey nutriment 

 to the larvae, and in this uterus the egg changes into the larva, and 

 subsequently into the pupa. As such the young is born, nearly of the 

 size of the mother, and enclosed in a hard, simple, smooth shell, with- 

 out any annular constrictions, and which shell is furnished at one 

 extremity with a cover. This springs off so soon as the pupa has 

 passed through this stage of its existence, and the perfect insect then 

 issues from the pupa case. We therefore here observe a true develop- 

 ment in the uterus similar to that of the mammalia, the larva receives 

 within the body of the mother, and by means of her, its first nutriment, 

 and in its state of puberty, consequently much later than the young 

 mammal, it comes forth into the world. This period also quickly 

 transpires, so that we may almost assert that the young one is capable 

 of re-producing the very moment it is born ; a solitary instance 

 unparalleled throughout the whole organic world. 



213. 



The number of the eggs laid by a female insect is generally very 

 great. We have above very recently shown the possibility, at least, of 

 a monstrous posterity in the flesh fly (Sarcophaga carnaria}, and yet 

 the female, according to De Geer, lays at the greatest number not more 

 than 160 eggs. This number, which may be considered as a very 

 general average, is in many instances exceeded ; in fact, we must feel 

 astounded at the incalculable multitudes which different authors give 

 as the produce of a single individual, numbers which are exceeded only 

 by the almost incredible productive powers of fishes. According to 

 Smeathman, the female of a Termites lays in one minute sixty eggs, 

 and therefore in one day more than 86,000, which, however, does not 

 by far terminate her period of laying. A small insect, which is found 

 in numbers upon the Chelidonium majus, Lin., namely, Aleyrodes 

 Chelidonii, Latr., (Tineaprolclclla,iim.), lays, according to Reaumur, 

 20,000 eggs (but the number of eggs is much exaggerated, it is only 

 between twenty and thirty f ) ; in the queen bee it varies from 5,000 

 to 6,000 : the ant lays from 4,000 to 5,000, the common wasp ( Vespa 



* Magaz. dcr Gcsellsch Naturf. Frcundc zu Berlin, (>. B. s. 131. 

 f Author's MS. addition. 



