322 WHEELER. [Vor. III. 
GENERAL REMARKS. 
a. Nuclear Continutty. 
It will be seen from the above descriptive paragraphs, that I 
maintain that a portion of the chromatin of the insect egg 
visibly survives in the decomposition of the germinal vesicle and 
can be traced through the divisions resulting in the formation 
of the two polar globules into the cleavage nucleus and _ its 
descendants. This conclusion, which has always been held by 
careful investigators of the transparent ova of lower forms, has 
been seriously questioned of late by two workers, Stuhlmann 
(45) and Henking (20). The former, after investigating a num- 
ber of Arthropod eggs in a superficial manner, comes to the 
conclusion that a stage exists in the ontogeny of the ovum when 
no traces of a nucleus can be demonstrated. Henking not 
only indorses this view, but describes in Opz/zo what are cer- 
tainly the products of division of the cleavage nucleus as arising 
de novo in different parts of the egg. 
As Blochmann (5) has pointed out the errors into which both 
investigators have fallen with far greater force than I can bring 
to bear on the subject, I will not increase the length of my 
paper by entering into a detailed account of their observations. 
Blochmann’s beautiful researches on the early stages of the egg 
have proved beyond a doubt that the Herapoda conform to the 
fecundative processes and method of polar-globule formation 
observed in other animals. 
That there is no moment when the nucleus ceases to extst as 
a nucleus seems to me to be proved by my Fig. 11, where the 
remains of the nuclear wall are still present while the spindle 
is forming. True, the wall is absent in the younger stage, Fig. 
10, and Fig. 11 may represent an exceptional case in which the 
wall has persisted longer than is usual, but it proves, neverthe- 
less, that the matter composing the nucleus does not diffuse 
through the protoplasm and ultimately recombine to form the 
nuclei which give rise to the blastoderm, as Henking (20) would 
have us believe. The nuclear wall is known to persist in 
another Arthropod till after the commencement of spindle forma- 
tion. I quote the following from the recent work of Weis- 
mann and Ischikawa (49): ‘“‘ Auch in den kleinen und dotterlosen 
