222 
W. A. HAS WELL. 
to the oviducts and their coeiomic apertures suggests that 
they may have some function in connection with the discharge- 
of the ovum. 
In living specimens active movements of a remarkable 
character were i-epeatedly observed to be taking place in the 
largest ova. The appearance presented is that of a nari-ow 
process being actively pushed inwards from the adjacent 
tissues towards the centre of the ovum ; but since there is no 
apparent mechanism present by which such an effect could 
be p>roduced, the movements must be the result of contrac- 
tions of the substance of the ovum itself — probably of the 
specialised superficial layer already referred to. The effect 
of such mov^ements is to bring the centi-ally placed nuclens 
within easy reach of the periphery. Two ends miglit pre- 
sumably be met by this peculiar change; the polar bodies 
miglit be separated off without the nucleus being* forced to 
travel from its usual central position through a dense mass of 
yolk-granules to the peripheiy, or the spermatozoon might 
be at once received into the neighbourhood of the nucleus of 
the ovum Avithout having to perform a like journey. 
Only in one case have I obtained sections of a specimen 
fixed while such movements Avere g’oing* on. In this case it 
Avas the second largest o\mm — here thickly beset Avith yolk- 
granules, in Avhich, as observed also in a living specimen, the 
phenomenon occurred. The ingroAvth in this case reaches 
from the outside nearly to the centre of the ovum, and appears 
as a narrow fissure filled Avith coelenchyme. The nucleus of 
the ovnm, situated near the bottom of this fissure, has become 
modified ; it has become distended, the nuclear membrane has 
almost disappeared though still traceable, and the chromatin 
has become broken up into numerous small granules. AVhether 
the circumstance that in this specimen numerous spermatozoa 
are to be detected fixed in the act of Avandering through the 
coelenchyme in the immediate neighbourhood of the fissure in 
the ovum has anything to do with the peculiar change in the 
latter must remain undetermined. For the iiiA^estigation of 
this problem and the folloAving out of the history of the 
