Prof.E. Claparede on the Reproduction 0/ Me Aphides. 365 



break up, resolving themselves into a sort of dust after the 

 destruction of their enveloping membrane. In many Aphides 

 these amoeboid corpuscles undergo a further degree of evolution 

 by their conversion into little unequal bacilli, which arc straight 

 or variously bent, immobile and colourless, and from 0*005 to 

 0*0.20 millimetre in length. One would easily be led to take 

 them for a parasitic vegetable production, but for having wit- 

 nessed all the successive phases of the transformation of these 

 elements/^ (Balbiani, lac. cit. pp. 548, 549.) 



These observations, and the interpretation which accompanies 

 them, are of prime importance. They form the cornerstone of 

 jNI. Balbiani's theory. If we look through the memoir of M. 

 Mecznikovv, otherwise so conscientious and full of details, we do 

 not find a single word upon these phenomena. It would be an 

 essential phase of development which has entirely escaped him. 



Let us now see what can be learnt on this point from the 

 Aphis of the Rose. The cells of the green mass, the boundaries 

 of which are always very distinct, present a clear circular 

 nucleus, 0*01 millim. in diameter, and furnished with a nucleo- 

 lus. They generate in their interior a number of homogeneous 

 spherical globules, among which may be distinguished a multi- 

 tude of exceedingly fine granules. These spherical globules 

 arc the dauyhter cells of M. Balbiani. Indeed it would appear that, 

 in his eyes, every granule is worthy of this name. Examined in 

 every way, with the best objectives of Smith and Beck, and 

 with the aid of llartnack's immersion lenses, these globules did 

 not show me anything which presented even a distant resem- 

 blance to a nucleus in the histological sense of that word. 



Even supposing that, entering into the views of M. Balbiani, 

 we assign the name and value of daughter cells to the globules 

 in question, we shall still be far from the theory of hermaphro- 

 ditism ; for the metamorphoses which this physiologist represents 

 them as undergoing cannot be regarded as normal phenomena. 

 The green mass, in fact, by no means disappears, but persists 

 icith all its characters long after the development of a new gene- 

 ration of embnjos has commenced in the interior of the embryo ; 

 moreover, as M. Mecznikow has also shown, it persists during 

 the whole life side by side with the fatty body. 



This first point, namely the persistence of the green mass, 

 being established in opposition to the description of M. Balbiani, 

 I find myself compelled to dispute the correctness of all that 

 relates to the formation of spermatic elements. M. Balbiani's 

 statement, moreover, is obscure and in contradiction with itself. 

 Thus this observer tells us that the daughter cells are soon 

 replaced by innumerable corpuscles, which appear like little 

 Ainoeha ; ^' but their form/* he adds, ^Uloes not seem to change 



