Pseudo-Reduction in the Oögenesis of Allolobophora foetida. 161 
above the eggs at the free end of the ovary although they have attained 
theü- maximum size have, as a rule, not reached the leptotene stage, the 
chromatin is homogene ons or has a delicate network structure. The deve- 
lopment of the eggs found in the receptaculum ovorum varies from the 
stage prior to the leptotene (Photo 12) to the first metaphase. We have 
found no exceptions to this. 
We are certainly justified in interpreting these stages which occur 
after the growth period of the egg as the stages which lead directly 
to the prophase of the first maturation division and they are therefore 
the stages corresponding to the spermatocyte prophases rather than the 
early pseudo-reduced group which disintegrates and disappears^). 
If the e\ddence in Allolohophora justifies the decision that the second 
group of reduced chromosomes is the homologue of the heterotype pro- 
phase of spermatogenesis then it raises the question as to the significance 
of the fü'st group. Popoff believes that this first group — this pseudo- 
reduction followed by disintegration instead of division, — presents e\’i- 
dence for R. Hertwig’s theory of cell division. He says : 
1) tVe would like to express our reglet that in a receut paper on these stages in 
Euschistus (09) we overlooked the fact that Wilson had called attention to the 
absence of a chromatin nucleolus in the earher stages. This omission was due to our 
conviction that the “great growth” period oi the egg and its subsequent leptotene, 
pachjdene and diplotene stages are the stages in the female which correspond to the 
spermatocyte leptotene, pachytene and diplotene stages. These stages in the egg 
have been conspicuously neglected by investigators of the Hemiptera Heteroptera 
and as far as we are aware not one word of description has been given of them. We 
find these stages in the female long after the period at which Wilson ünds the 
young oöcytes he mentions. We have never found them in the ovary of “just 
emerged adults” of any of the Hemiptera studied by us nor even in the females ex- 
amined several days after the last moult. Wilson’s description would iudicate that 
he is refening to stages similar to those in our Photos 7 and 8 of this paper, for he 
sees a contraction stage which finally culminates in an oöcyte with “a fine reticular 
structure”. It is at this point that we believe the growth period of the egg begins 
and it is the long grovTh period foUowing this stage that presumably offers the most 
favorable opportunity for the study of the nucleoli in the egg. In all the eggs of the 
three Hemipteran forms we have thus far examined the plasmosome appears as a very 
large achromatic body more than four times as large as the chromatin nucleolus of 
the male. See Foot and Strobell (09) Photos 20 to 24. In the stages studied by 
Wilson he describes as “probable plasmosomes” one or two deeply staining nucleolus- 
like bodies “much smaller” than the chromosome nucleolus of the spermatocyte. We 
can Support Wilson’s observations as to the presence of an oöcyte contraction stage 
in the ovary and we can add to these observations the presence of a pseudo-reduc- 
tion, but both these phenomena occur before the growth period, as we understand it 
i. e. the period initiated by the young oöcyte, with its typical network or granulär 
chromatic structure. 
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