70 Dr. Burnett on the Development of Viviparous Aphides. 
Morrem,* who made somewhat extended researches on the 
anatomy of Aphis persica, and especially of its generative organs, 
advanced the novel theory, that these broods were developed in 
the body of the virgin parent, by a previously organized tissue 
becoming individualized and asstming an independent life, ex- 
actly, as he believed, to be the case with Entozoa. To each an 
all of these views, it scarcely need be said that they would be 
wholly inadmissible according to the present established doc- 
trines of physiological science, even had we no directly contro- 
verting observations. 
ere are other explanations or views which deserve more 
attention. The first of these is that advanced by Kirby and 
Spence.t According to them “One conjunction of the sexes 
wittines for the impregnation of all the females that in a succession 
of generations spring from that union.” In support of the rea- 
sonableness of this hypothesis, they quote several instances which 
they regard as of analogous character ; thus, they say in regard 
to the hive-bee, that ‘‘a single intercourse with the male fertil- 
izes all the eggs that are laid for the space of two-years.” 
In this connection should be mentioned the similar hypothesis 
advanced for a like purpose by Jourdan.{ According to him 
many Lepidoptera lay fertile eggs when completely isolated from 
the males: such are, Huprepsia casta, Episema ceruleocephala, 
Gastropacha potatoria, Gi. Eb Ni a nee G. pint, Sphinx ligus- 
irt, Smerinthus populi and Bom 
But, all these cases have really ata analogy with that of 
the Aphides in question; for there is not, as with these last, a 
succession of innately fertile individuals, but oy females which 
are capable of — — broods from a single coitus, or 
after having been long removed from the males which may even 
then be dead.$ Late stonrelios upon the minute anatomy of 
All these insects which are thus capable of asthe fecundated eggs 
again and again after the first impregnation, have a Recepiaculum 
* Morrem, Anat. de Aphis persicae, in the Ann. d. Se. Nat., v. 1836, p. 90. 
+ Kirby and Spence, Pyne to otomalseyt iv, 
Jin NO f Li 4 
§ Siebold has oe observations — allied aoe occurring in the Psy- 
shown t 
: case. 
shown that there is propagation sine aoe a exactly as occurs with the Aphides. 
See Ueber die Fortpnsng pion” ‘syche: Ein rig. zur Naturgeschichte der 
bold & Kolliker’s Zeitsch. i 93; 
researches on Jal ia, see his Bericht tb. d. enteral _ Artin d. schles. 
im J. 1850—or its English transl. in the Trans. o: 
