280 If. LYNDHURST DUKK. 



from the debris of the old nucleus is obvious from figs. 14 

 and 15. 



Siedlecki, in his work on the karyosome of Caryotropha 

 (19), reviewing the role played by this body in Coccidia, 

 points out that while in some types the karyosome plays a 

 purely vegetative part, in others it has definite responsibilities 

 regarding the reproductive functions. The latter appears to 

 be the case in Metamera schubergi. If, as I believe 

 to be the case, the daughter-nuclei reform their karyosomes, 

 may not these daughter-nuclei — which arc, after the upheaval 

 of the trophozoite nucleus during its first division, presumably 

 sexual in nature — throw some light on the functions of the 

 karyosome ? If the latter be purely vegetative in function, 

 why should it recur in the daughter-nuclei, which, with their 

 two centrosomes, are plainly not in a vegetative condition? 



In the face of the facts it is certainly a reasonable sugges- 

 tion that the original karyosome consists of two elements at 

 least. The one of these is thrown out at the first division of 

 the nucleus, and is of no further use in the formation of the 

 daughter-nuclei; the other is of vital importance in the 

 propagation of the species, as realised in the sexual gametes. 

 In the daughter-karyosomes only one of these components 

 persists — i. e. that part essential to nuclear division; the 

 other part — for which, in the active reproductive processes 

 now proceeding no need remains — is not represented. Thus, 

 in the daughter-spindles no karyosome remnants are seen. 

 This is hardly the place for a discussion on the binuclearity 

 hypotheses, so ably deak with by Dobell (8), but the above- 

 mentioned differentiation of the karyosome constituents is 

 sufficiently suggestive. On the one hand, the vegetative and 

 reproductive elements of Goldschmidt's theory may be seen 

 in the original karyosome residue and the so-to-speak more 

 intense daughter-karyosome respectively. On the other hand, 

 one is equally justified in assuming that the karyosome 

 residue merely represents elements whose life is over and 

 whose functions are exhausted, while the perpetuated 

 remainder persists in the daughter-karyosomes, which are 



