Conti', towards tbe Embryolog)^ and Anatomy of Polisles pallipes. 177 



tlie ceuter. In the older oöcytes he couid not find any trace of 

 the nucleiis. 



In Bomhus, Stuhlmann found that some of the »Dotterkerne« 

 appeared very similar to the regulär nucleus; others do not. The 

 opening between egg- and nurse Chamber was observed and once 

 he saw three of the »Ballen« in this passageway »welche einen Uber- 

 gang zwischen den Kernen des Follikelepithels zu den Dotterkernen 

 zu bilden scheinen«. He suggested the possibility of these being 

 cells which had passed from the outside into the egg but did not 

 think it at all probable. The »Ballen« at the upper pole of the 

 oöcyte remain but those at the lower pole are dissolved, the latter 

 being the older, disappear first. 



KoRSCHELT (18) found nuclei with nucleoli in the terminal 

 filament but was unable to distinguish cell boundaries. Proximal to 

 this the nuclei became larger and in the terminal Chamber he found 

 that some grew more rapidly than others; in this region he found 

 cell boundaries. At this place »zwischen den Kernen der Keimzellen 

 und den der jüngsten Eianlagen ist kein Unterschied zu bemerken«. 

 Later he could distinguish the oöcytes by their lighter appearance 

 and larger size. In the oöcyte nucleus the chromatin forms in large 

 masses. Distally in the end Chamber the nuclei have the same 

 structure as those in the terminal filament but they were larger. 

 The large nuclei become those of the oöcyte, the smaller ones 

 surrounding these form the nurse -cells. By Bytisciis and Musca 

 he found these »Keimzellen«, differentiating into oöcytes and nurse- 

 cells but in Bomhus to oöcytes only. The nurse-cells group them- 

 selves first at the side and then distal to the oöcyte; they increase 

 in number and their nuclei are larger than those of the oöcytes. 



Paulcke (25) found in the bee no external or internal boundary 

 between the terminal filament and the end Chamber. In the upper 

 part of the former are many elongated nuclei lying across the tubule 

 ^Leydig [20]), which are embedded in a mass of protoplasm. At 

 the place where these small nuclei become larger there is a marked 

 transverse striation in the tubule; in this region cell boundaries 

 appear and nucleoli in the nuclei. These are now either oogonia or 

 they remain unchanged and become the epithelial cells. In the former 

 the chromatin in the nucleus becomes thicker, at first it forms a 

 mass with two nucleoli which later disappear. He describes both 

 a synapsis zone and a zone of differentiation. Proximal to the former 

 zone small cells (nurse-cells) very much like the undifferentiated 



