Colitr. towards the Embryology and Anatomy of Polistes pallipes. 185 



miglit be that the cells of a group are attached to the wall of the 

 tnbiile near each other, and in some way remain so, or become in 

 part fused with each other. The central portion from which they all 

 come, or to which they are all attached, is, in older stages, of a 

 darker cytoplasm than the rest of the cell (Fig. 16) and this common 

 central portion is very distinct. 



KOvary B. Passing to a somewhat older larva, one 16,5 mm long, 

 re notice that changes have taken place, especially, in the growth 

 f the tubules themselves (Fig. 9); each is in this larva 0,6 mm long. 

 A Single tubule shows a proximal part, very different from the rest, 

 (Fig. 9 odt) which later develops into the oviduct. This same 

 differentiation was also seen in younger larvae from 12 to 15 mm 

 long. These parts would probably correspond to the »Endfaden, 

 Keimfach und Ausführungsgang«, the three divisions given by 

 Hexking (13) for the ovary of the larva of Pyrrhocoris. Within the • 

 proximal part, the cells are different from those found in the rest of 

 the tubule; they are filled with large vacuoles which, under a low 

 power, gives them a much lighter appearance than the others; their 

 nuclei are smaller than those in the other two parts of the tubule, 

 but differ very little in structure. The cells are long and narrow, 

 and arranged across the tubule; no central lumen has as yet appeared 

 in the future oviduct. The middle section of the tubule (Fig. 9 ov)^ 

 shows a great similarity throughout, the nuclei are nearly all large 

 and spherical, their cells also large, and generally rounded or poly- 

 hedral. These nuclei (Fig. 10), are similar to the last one figured; 

 each has generally two nucleoli, a number of chromatin granules, 

 and connecting achromatin Strands. These nuclei are 0,0085 mm in 

 diameter. The chromatin granules are slightly larger than in the 

 last stage, and the achromatin enlarges to a small irregulär mass 

 around each one. Along the margin of this middle portion of the 

 tubule are a number of small, ovoid nuclei, each having about the 

 same structure (Fig. 11) as those in the distal part. In this latter 

 part nearly all the nuclei have an oval form (Fig. 12), each with 

 two to four, generally two, nucleoli, small chromatin granules and a 

 reticulum, of which one or two Strands can generally be traced 

 across the nucleus from side to side. The cells are elongated and 

 both they, and their nuclei, lie with the long axis across the tubule. 

 One notices that the cells are closely crowded together. The nuclei 

 lie mostly near the margin of the tubule, only a few being found in 



