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Wm. S. Marshall, 



to those with chromosomes, and thus show that they are older. Ko 

 division foUows this stage in the oöcytes, but the threads later become 

 arranged in synapsis. In Polistes we find that during synapsis the 

 cell boimdaries are very easily seen, but Paulcke (25) for Apis and 

 Geünberg (12) in Pieris failed to find them. In the many ovaries 

 of about this same age which we examined, the nuclei of the oöcytes 

 always took this order, and never in the young pupa of Polistes were 

 synapsis nuclei found at any place except in the proximal part of 

 the median portion of the tubule; always in front of these were nuclei 

 similar in structure to figure 44. Synapsis nuclei were found, two 

 or three in a section, or often none at all; they showed a Variation 

 in structure. Some have a large irregulär mass of achromatin in 

 which lie many deeply staining chromatin granules, and from which 

 nearly all trace of the threads have disappeared, others show a few 

 threads in this mass which can be Seen protruding from or running 

 through it (Fig. 45 a). We failed to find such a regularity in structure 

 and polarization as Giardina (9) found in the oöcytes of Mantis. In 

 most of these nuclei a few odd pieces of the beaded threads were 

 scattered through them opposite the large mass. After this stage the 

 threads become evenly distributed throughout the nucleus; whether 

 or not they are of equal length we are unable to say; in most nuclei 

 they were of about the same length, but in many, at least one thread 

 was present, which was equal in length to the diameter of the 

 nucleus (Fig. 46 a). This last oöcyte is one of the oldest in this 

 ovary and, as is shown by its position, (Fig. 37, position 46), lies just 

 distal to the oviduct. 



In the proximal part of the median portion of the tubule we find 

 a new form of nurse-cell nucleus. In this (Figs. 45 b and 46 h) a 

 Single irregulär achromatin mass lies at, or near, the center and on, 

 or near it, a few chromatin granules; achromatin Strands pass from 

 this central part to the nuclear membrane, these and others form an 

 irregulär network the Strands of which contain a number of chromatin 

 granules. We have here the nucleus of a nurse cell after all its 

 divisions have been completed; this same form will again be seen in 

 the older ovaries. 



Ovary G. We select, from a slightly older pupa, a few nuclei 

 for description to show that the same order is found here as we have 

 just observed in Ovary F. Near the boundary between the distal and 

 the middle parts of the tubule, we notice the same two kinds of 



