332 PHYSIOLOGY. 



If, therefore, an intermixture of the semen with the egg germ could 

 take place, it must occur likewise in insects in the uterus and not in 

 the ovary. But as much may be said against this intermixture in 

 the superior animals, viz. from extra uterinal and tubular pregnancy, we 

 find in insects also the successive development of several consecutive 

 eggs in the same tube standing in the way of its reception, for the 

 lowest egg only could come in contact with the spermen, and 

 without the re-adoption of the already obsolete opinion of the aura 

 seminalis, which Spallanzani has shown to be erroneous, we are 

 left precisely in the same situation by adopting or rejecting it. 

 We can consequently merely ascribe the incipient development of 

 the germs to the formative energy imparted to the female body by 

 the presence of the male semen, and to the stimulating excitement at 

 the time of immission. These germs are proportionally larger and 

 more perfect the closer they lie to the uterus, and, consequently, their 

 development must be progressive, if a determinate time and proportion 

 be given within which alone it can be effected, and this it appears 

 absolutely necessary to adopt. Nevertheless, the semen may possibly 

 pass from the oviducts to the tubes, and here come in contact with the 

 lowest egg, which would thereby acquire its perfect development a 

 certain time before the formation of the shell. Thus, both the dynamical 

 and mechanical views have justice clone them. 



209. 



But before we pursue further the development of the egg, stimulated 

 by impregnation, we must investigate the degree of participation the 

 several appendages of the sexual organs have had in this impregnation as 

 well as in the formation of the egg. We have already become acquainted 

 with the function of one of the appendages of the female organs, viz. the 

 spermatheca; the rest are, both in the female and in the male, according 

 to what we have above indicated ( 140 and 150), organs which 

 secrete a gluten. Their form, as we have there shown, proves this, 

 from its resembling that of the majority of the glandular organs in 

 insects, and also from the analogy of the superior animals, in which 

 similar glands are found in connexion with the genitals. But if their 

 secretion be positively a gluten, we may ask, what is the purpose of 

 this gluten in relation to impregnation and the formation of the egg ? 

 That it is not absolutely necessary, is proved by the many instances in 



