160 
Katharine Foot and E. C. Strobell 
A cai'cful coinparison of tlie relative sizes of the ehromosomes — even 
at the same stage of development — frequently shows significant in'egulari- 
ties, but in this paper we have selected none of the preparations with a 
\iew of demonstrating this point. We would call attention however to 
Photos 18 and 19. The relative sizes of the ehromosomes of these two 
preparations are by no means identical. More raarked inconstancy in the 
relative size of the ehromosomes at the same stage of development is com- 
mon in Älloloiophora and ve called attention to a similar variability in 
the spermatogenesis of Anasa tristis (07). 
Inconstancy in the form, size and number of the ehromosomes has 
been frequently noted for many forms, and all such observations present 
a serious obstacle to the theory of the indmduality of the clu'omosomes, 
though they do not conflict with the behef that the ehromosomes are “an 
expression of the organizing function of the cell as a whole”. 
(Farmer 07, p. 455). 
Conclusion. 
Gregoire’s criticism of Popoff’s conclusions challenges an answer to 
the question which of these two groups of reduced ehromosomes in the 
oöcyte is the homologue of the heterotype prophase group of the sper- 
matogenesis. Is it the group -which is present before the “grand accrois- 
senient” Photos 2 and 3, oris it the group which appears after the ,, grand 
accroissement” Photo 19? 
Gregoire concludes that the former group is the homologue of the 
heterotype prophase in spermatogenesis, basing this conclusion on the 
fact that in Paludim Popoff was able to trace in only the first group, the 
successive stages of the development characteristic of the heterotype pro- 
phase of spermatogenesis. He concludes therefore that the cliromosomes 
of the second group have not been formed anew and have persisted as such 
througli the entire “gTand accroissement”. 
IVe have shown that this reasoning does not hold true for Allolobo- 
phora, for the Steps characteristic of the development of the spermatocyte 
heterotype prophase can be clearly demontrated in the development of 
the ehromosomes of the oöcyte heterotype prophase, which occurs after 
the egg has reached its maximum growth, and these are the chromo- 
somes of the first metaphase. 
Eggs found at the free end of the ovary (text-fig.) have certainly 
passed through the stage of “grand accroissement” and the leptotene, 
pachy teile and diplotene stages of the second group are found m eggs 
which have left the ovary and are in the receptaculum ovorum. As stated 
