308 C. CLIFFORD DOBELL. 
(5) Cells with only a propagatory nucleus, but which 
can, of course regenerate a somatic, are found only in the 
gametes of protozoa, and in certain nutritive cells of the 
ovary—possibly also in many sorts of spermatozoa.” 
“ (6) Cells with only a somatic nucleus are also possible : 
the residuum of gregarines, the reduced cells of Ascaris, 
certain muscle cells.” 
In the first place, it must be noted that the term ‘ binu- 
clearity ” (‘ Doppelkernigkeit”) is not a happy one. The 
conception is not of two nuclei but of two kinds of 
chromatin, and in this it differs from the other binuclearity 
hypothesis (Schaudinn-Prowazek-Hartmann, cf. p. 311). 
The idea would be more exactly expressed by a word such as 
“ dichromaticity”’ (‘‘ Dichromatizitit”). An actual somato- 
reproductive binuclearity exists only in such forms as the 
Infusoria, where somatic nucleus (meganucleus) and propaga- 
tory nucleus (micronucleus) areoften completely separate. This 
arrangement—which, for Goldschmidt, shows a resolution of 
the nucleus into its primary parts—is, for me, merely a mark of 
the high degree of differentiation which the Infusoria exhibit 
in so many other ways besides. ‘l'o my mind it is a specialisa- 
tion, not a simplification. ‘There is, moreover, some evidence 
to show that even here the two nuclei do not necessarily con- 
sist of two essentially different kinds of nuclear substance. 
For, as has been abundantly proved, the micronucleus can 
form a meganucleus after conjugation; and conversely, the 
meganucleus can probably form a micronucleus (Le Dantec, 
197); 
It is further to be noted that the “ propagatory nucleus,” 
far from being entirely concerned with reproduction, can in 
certain cases exhibit independent powers of metabolism and 
erowth.' Itisas unjustifiable to maintain that the micro- 
1 Cf. Mastigina, “The sporetia . . . must indeed nourish and 
reproduce themselves independently. And we must assume the same 
for the . . . chromidial net of the shelled rhizopods” (Gold- 
schmidt, 07). And further, in Arcella: “ The generative function (i.e. 
of the chromidial net) is indubitable. On the other hand, it is equally 
