230 W. WALDEYER. 
remains in the egg to form the female pronucleus (“ Eikern”’ 
of O. Hertwig). 
In one important point E. van Beneden puts forward an 
anomalous view, since he believes that in the formation of the first 
directive corpuscle complete nuclear threads or loops are 
extruded. Carnoy (l.c.), too, supports this opinion. But this 
is not tenable, according to the researches of Nussbaum (147, 
148) , Zacharias (210), Boveri (36), and Kultschitzky (115,116): 
itis only aftera previous splitting of the segments or chro- 
mosomes, as in ordinary mitosis, that half of the secondary 
threads (or half-threads) are used to form the directive cor- 
puscle. Recently van Gehuchten (77) has supported Carnoy’s 
statement, which, although it differs in other points, agrees 
essentially with that of E. van Beneden, viz. in the extrusion 
of complete chromosomes. Carnoy aud van Gehuchten extend 
this to both directive corpuscles. If this account is correct the 
formation of the directive corpuscles cannot be compared with 
ordinary mitosis, at least not by those who regard the splitting 
of the primary chromosomes before the stage of metakinesis 
as an essential phenomenon in mitotic division ; it is in this way 
that EH. van Beneden regards the matter. For Carnoy the absence 
of splitting will be no hindrance, since, as was stated, he does 
not regard Flemming’s longitudinal splitting as essential. Van 
Gehuchten relies chiefly on the fact that in the youngest eggs 
of Ascaris, the skein divides into eight segments, of which 
six will by degrees be extruded and two will remain. 
I have recently had the opportunity of examining van 
Gehuchten’s preparations; they show distinctly, as he has 
described and figured, that before the extrusion of the first 
directive corpuscle eight very short, slightly curved rods are 
present. Four of these rods are extruded to form the first 
directive corpuscle, and two for the second. Even in a very 
young egg of Ascaris these eight rods can be seen. I am 
not in a position at present to clear up the differences which 
exist between the preparations of Kultschitzky, which I have 
also seen, and those of van Gehuchten. It is true that each 
has employed different methods. 
