lvii 
vitellus” of Prof. Huxley, but the description given by M. Balbiani 
of the development of the bacilli suggests, in many respects, a dis- 
integration of the natural tissues, and a development of parasitic 
growth, rather than the ordinary and natural production of sexual 
elements. 
On passing to the oviparous form we shall meet with additional 
difficulties. 
The “ male apparatus,” as already described, occurs alike in both 
sexes, in the males as well as in the females, and with characters 
scarcely differing from those which it presented in the viviparous spe- 
cimens. ‘The true male generative organs are homologically the same 
as the female. There are not two rudimentary organs of which one 
is developed in one sex and the other in the other; but there isa 
single original rudiment, which is developed in one manner in the 
female, in a different manner in the male, and which in both cases 
contains the so-called ‘‘ embryonic male organ.” 
This “embryonic male organ”’ is evidently, therefore, a perfectly 
distinct organ from an ordinary testis, and, as M. Balbiani has 
observed it in other animals besides Aphides, we shall await with 
interest some further communications on the subject. In the female 
Aphis he describes it as contained in the ovary, and as producing 
cells which evidently correspond with the seminal corpuscles of the 
viviparous form. ‘“ These facts,” he concludes, “ evidently indicate 
that the egg has already, while in the ovary, undergone a first fecun- 
dation, with which the male has nothing to do, and the effect of which 
is limited to the production of the generative elements of the future 
animal.” 
Some years ago* I attempted to show that there are two distinct 
kinds of Spermatozoa among the Annulosa, and I ventured to 
suggest that their functions were probably different. But however 
much I might be tempted to claim these observations of M. Bal- 
biani as confirmatory of my views, I cannot but feel that fresh evi- 
dence is required that his “ embryonic male organ” has really the 
nature and functions which he attributes to it. 
Although our late President, Mr. Pascoe, alluded briefly, in his 
last Address, to the remarkable discovery made by Prof. Wagner 
that certain dipterous larve possess the power of agamic repro- 
* Phil. Trans. 1861. 
G 
