ARTIFICIAL PARTHENOGENESIS IN PODARKE OBSCURA. 237 



amoeboid movement, though, as the egg membrane is closely 

 applied to the surface of the egg, these movements are not as 

 noticeable as in other animals. They were, however, sufficient 

 in amount to make camera drawings impracticable. The pre- 

 served material shows that the cytoplasm is apparently broken 

 up into distinct globules, though from the appearance presented 

 by the living egg I think it altogether probable that they are 

 really in communication with one another, these "globules" be- 

 ing really amoeboid processes. As seen in the drawings, these 

 preparations bear a superficial resemblance to a cleaving egg. 

 There is, however, absolutely no resemblance to the normal 

 cleavage, and a study of the stained material shows that the 

 division is one involving only the cytoplasm, the chromatin being 

 massed together in one of the spheres. This sphere is usually, 

 though not always, larger than the 

 others. (In the egg from which 

 Fig. 3 was drawn, the chromatin, 

 except the small bit seen in one of 

 the upper cells, was in a large cell 

 on the side of the egg opposite that 

 from which the drawing was made.) 



In the second of the above-de- FIG. 4. " Two-cell" stage. The 

 scribed cases, cleavage involves both nuclear matter is scattered through 



the cytoplasm. Preserved material. 



nucleus and cytoplasm. In Fig. 4 



several asters are plainly to be seen in each cell, which leads to 

 the suggestion that possibly it is upon the presence or absence 

 of these that the differences in nuclear activity are dependent. 

 Division of these eggs is apparently complete. In the two-cell 

 stage the greatest possible variations in size between the two cells 

 appear, the division being sometimes nearly equal, as in Fig. 4 

 and again very unequal. I have no reason to believe that this 

 division is karyokinetic. It seems rather as if one of the cells is 

 to be regarded as a lobe of protoplasm which contains some of 

 the nuclear material, and may later become completely divided 

 by a membrane from the other cell. Instead of two cells, a 

 trefoil stage may appear. 



What I interpret as later developments of the stage just de- 

 scribed are shown in Figs. 6 and /. These divisions are appar- 



