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Wm. S. Marshall, 



distal end. In this stage, ovary H, the cells in synapsis must be 

 sought much further up (Fig. 52 Syn). Following from this place 

 the development of the oöcytes we find, as in the last stages, that 

 after synapsis the long, beaded threads distribute themselves throughout 

 the nucleus. This condition remains for some time unaltered but, 

 by the growth of the nucleus, the threads are separated more from 

 each other; each one is beaded, the chromatin granules do not stain 

 deeply and only appear very dark at the ends of the threads which 

 one sees in optical, or real, section. As the nucleus grows the threads 

 become clearer and more distinct (Fig. 53) and we reach a place, 

 (Fig. 52, Position 54), where we find them growing quite irregulär 

 (Fig. 54), more ragged along their edges, and loosing the regularity 

 within the nucleus they earlier showed. The threads are still beaded 

 and are the only Contents of the nuclei. The slight irregularity 

 which we here notice is the beginning of their disruption, it becomes 

 more marked (Fig. 55) and, while the threads still show a slight 

 beaded structure, they have entirely lost the regularity which they 

 had in the younger oöcytes. The oldest oöcyte (Fig. 56) in this 

 tubule shows even a greater irregularity and the chromatin granules 

 have gathered in achromatin masses. Paulcke (25) notices that in 

 Apis this change takes place when the Chambers are being formed. 

 »Mit Beginn der Kammerbildung verliert das Keimbläschen seine vor- 

 her so charakteristische feinfädige, gerüstartige Chromatinstructur. « 

 In each of the last two oöcyte nuclei an achromatin nucleolus 

 has appeared which we failed to notice in any of the preceding 

 stages. 



In all the oöcytes which we have figured from this tubule a 

 yolk-nucleus was present. It is a deeply staining, round or ovoid, 

 body, lying in a clear space within the cell. This has been drawn 

 only in the oldest oöcyte (Fig. 56). 



Ovary I. Passing next to the study of an ovary from a wasp 

 which has been but a few hours out of the nest, we notice that 

 many changes have taken place. The oldest oöcyte already lies in 

 its own Chamber separated from the nurse cells, also in their own 

 Chamber, which lie distal to it. The oldest oöcyte is the only one 

 which, externally, shows a complete Chamber formation; in a longitudinal 

 section, however, one notices that the Separation has taken place in 

 the three next oldest oöcytes (Fig. 57). No distinct terminal filament 

 is noticeable, but for a distance of about 0,3 mm from the tip, many 



