132 William A. Kepiier. 



been just about to enter the egg cytoplasm. It appears quite probable, 

 therefore, that these migrated nuclei, or as Gross, '01, calls them, 

 "einwandernde Ei)ithelkerne," have been furnished bv the follicle 

 epithelium. 



The migration suggests the observations made by Metcalf on the 

 ova of Salpa ; but the two phenomena differ functionally. In Salpa 

 the nuclei of the follicle epithelium are taken into the egg cytoplasm 

 primarily as a supply of food for the ovum. In Scolia dubia, on the 

 other hand, they have migrated primarily to become the handlers 

 of food material and only when this primary function is terminated 

 do they function in the same manner as the migrated nuclei of Salpa. 



At the beginning of the second phase of nutrition when the nurse 

 cells are about to send food material into the cs^g cell, but one or two 

 of these migrated nuclei are present (Fig. 6). As the egg cell 

 grows and the elaboration of yolk is begun, these greatly increase 

 in number. Along the distal periphery of the egg cell they then 

 form a closely packed layer of clearly defined, rounded to oval nuclei, 

 each of which has a definite nuclear reticulum and a conspicuous 

 nucleolus. They lie in less numbers about the entire periphery of 

 the egg cytoplasm. Those found below the distal fourth of the egg 

 cell are smaller and stain more readily. Have all of these many 

 nuclei come from the follicle epithelium ? 



In Scolia dubia during the early stages and in favorable places 

 within older egg cells, groups of ova are met with in which one or 

 two large migrated nuclei are found surrounded by smaller ones 

 (Fig. 8). In many other cases large nuclei are found, on which 

 there is a partial constriction which divides the nucleus into a 

 large and a small lobe. In all such cases two nucleoli are present ; 

 while only few nuclei with two nucleoli and with no constriction 

 were observed (Fig. 9.) These observations have led to the interpre- 

 tation that the migrated follicle nuclei propagate within the egg cyto- 

 plasm by means of amitosis, which results in each case in daughter 

 nuclei of unequal size. In any cases where the egg nucleus is un- 

 aided by other nuclei Dotterkerne or yolk nuclei are found. These 

 are so frequent that to give examples in this connection is uncaUed 

 for. In the ovum of Vcspa vulgaris described by Gross, '01, as 



