Insects. 4495 



sion of innately fertile individuals, but only females which are 

 capable of producing several broods from a single coitus, or after having 

 been long removed from the males, which may even then be dead. 

 Late researches upon the minute anatomy of the generative organs of 

 insects have furnished results by which these phenomena, seemingly 

 strange at first, can be explained. All these insects which are thus 

 capable of laying fecundated eggs again and again after the first im- 

 pregnation have a receptaculwm seminis connecting with the oviduct, 

 in which the semen is deposited during coition, and where it may be 

 preserved without losing its vitalizing power for several months. 

 Thus, by this provision the males, having copulated with the females 

 in the autumn, may immediately die, while these last, hybernating, 

 produce in the spring fertile ova ; and in the instance of the Bombus 

 americana such a coition suffices for all the three broods which 

 are produced the ensuing summer. 



Another explanation of these curious phenomena, and which 

 has attracted some attention, as well from its singularity as from the 

 eminence of its propounder, is that of Owen, advanced in his Hun- 

 terian Lectures in 1843. 



He affirms that the larval Aphides are productive, in virtue of 

 the successive continuation from brood to brood, of a portion of the 

 primitively fertilized germ, and which material product or leaven is 

 not exhausted until nine to eleven generations. I will quote his own 

 language. 



" In the Aphides, the corresponding vitelline cells retain their share 

 of the fecundating principle (which was diffused through the parent 

 egg by the alternating, fissiparous, liquefactive and assimilative pro- 

 cesses) in so potent a degree, that a certain growth and nutritive 

 vigour in the insect suffice to set on foot in the ovarian nucleated cells 

 a repetition of the fissiparous and assimilative process, by which they 

 transform themselves in their turn into productive insects ; and the 

 fecundating force is not exhausted by such successive subdivision un- 

 til a seventh, ninth or eleventh generation." 



This same doctrine, the successive inheritance of a portion of the 

 primary germ-mass from brood to brood, and by means of which the 

 fertile germs are continued, — this doctrine, I say, is repeated in full in 

 this author's work on Parthenogenesis, and I will here quote one sen- 

 tence, not only in illustration of this, but to show how different his 

 own observations on the development of these animals are from mine 

 just described. He says, " One sees such portion of the germ-mass 

 taken into the semitransparent body of the embryo Aphis, like the 



