Contr. towards the Embryology and Anatomy of Polistes pallipes. 195 



nuclei; the oöcyte nucleus (Fig. 47 a) shows the same structure we 

 have already described; it is also found a little distance down the 

 tubule (Fig. 48 a). In the nucleus of the primitive nurse-cells we 

 also find a similarity between this and the younger stages. A little 

 proximal to the boundary we just mentioned, we find nuclei with the 

 spherical chromatin body (Fig. 48 h) we have already noticed in 

 younger ovaries. 



In the nuclei of the primitive nurse-cells we find that the same 

 changes, as already noted, take place, and that proximally, in the 

 median portion of the tubule, are a few nuclei with chromosomes. 

 In this region the light colored nuclei are also found and they show 

 the same Variation in size and in Contents as in the earlier stages. 

 Xear the proximal end the nurse-cell nuclei show the structure we 

 have already said was characteristic for them after division has ceased, 

 and they become the permanent nurse-cells (Fig. 51 h). 



The oöcyte nucleus also shows a chromosome formation but here, 

 as in the nurse cells, this stage is notabundant [Fig. 50). Synapsis 

 stages are found, and after these the beaded threads become evenly 

 distributed throughout the nucleus (Fig. 51 a). In both this and the 

 preceding stage, dividing cells could be fouud in nearly every part 

 of the median portion of the tubule. 



Ovary H. The next stage we will consider, an older pupa, is 

 one in which the oldest oöcyte and its accompaning nurse-cells are 

 arranged to form the first Chamber. In older stages w^e shall show 

 that Chambers are not at first formed as egg- and nurse Chamber, 

 this Separation Coming later in the development, but that the oöcyte 

 and its accompaning nurse cells are together in a common Chamber. 

 In any tubule of this ovary we find, proximally, an oöcyte and 

 accompaning nurse cells lying in a Chamber. Distal to this group 

 lie many other oöcytes, but none show any indication of Chamber 

 formation, although the few oldest ones, have grouped around them 

 those nurse-cells which will later form their nurse Chamber (Fig. 52). 

 In neither this nor other Chambers could we find the regulär 

 arrangement of the nurse cells as described by Paulcke (25) for 

 the bee. 



In the last stages, ovaries F and G, we noticed that the zone in 

 which the synapsis nuclei lay, was near the proximal end of the 

 middle portion of the tubule (Fig. 37, position 45) ; as development 

 goes on this zone changes its relative position and moves toward the 



