220 MARY T. HARMAN 
a process of division may be determined only by observation. If 
the time had been determined for a cell to divide mitotically and 
for a cell of the same material under the same conditions to 
divide amitotically, Professor Child’s statement would have 
been more nearly justified. 
If the fact that the chromatin is in the form of a spireme be 
an indication that cell-division is taking place by mitosis, in 
figure I, plate 5, we might interpret the large nucleus as dividing 
mitotically and the smaller nuclei amitotically. However, figures 
H and I, plate 7, show both large and small nuclei in a connected 
spireme. It seems that it is perfectly possible that the differ- 
ence in the character of the chromatin in the nuclei shown in 
figure I, plate 5, might be interpreted as different stages of the 
prophase. Mitosis unquestionably occurs in the smaller nuclei 
as well as in the larger ones. Figure C of plate 7, shows a spin- 
dle in the metaphase of mitotic division. Since the segmenting 
ovum is a syncytium, the size of the cell cannot be determined, 
but the nucleus giving rise to the spindle was undoubtedly smaller 
than the largest nucleus in the ovum. The nuclei in the process 
of reconstruction shown in figure G of the same plate, are un- 
doubtedly smaller than the large nucleus of the same ovum and 
could not greatly exceed in size any nucleus shown in the figure. 
The mitotic figures shown in figures A and B of this plate could 
not produce daughter nuclei which would exceed in size the 
other nucleus of the respective ova. 
Granted that nuclei which lie in close contact: afford evidence 
that nuclear division may have taken place amitotically and 
that the imperfect spireme is no indication that mitosis is taking 
place, how could the position of the nuclei forming a triangle in 
figure L, plate 7, be explained? The nuclei are of nearly the 
same size and lie in very close contact, although the boundaries 
between them are clearly visible. If they have come about by 
the process of amitosis, which nuclei were the first to constrict 
off? It seems that it would be necessary to assume an unequal 
division and that one division has followed the other very closely 
before the nuclei have moved apart. Without these assump- 
tions, I see no possible explanation for this arrangement of the 
