374 LEWIS HKNRY GOUGH. 



is necessary to obtain material where mitoses are taking 

 place, as they pass very quickly. Usually only two or three 

 segments at the most show mitoses ; those before and after 

 not containing any; the difficulty of obtaining sections through 

 the exact portion of the strobila is consequently easy to 

 appreciate. There appear to be four chromosomes, the exact 

 number being hard to count, as the karyokinetic figure is 

 very small. I have not been able to make out the fate of 

 the pole bodies, but when the eggs pass into the oviduct 

 they are no longer to be found. The matured oocytes are 

 not enclosed in a membrane of any kind; they arrive naked 

 in the uterus, not having a membrane of their own, and 

 not receiving a shell, as there is no shell-gland. The 

 fertilised oocytes are at first not enclosed in shells or by 

 membranes. Fig. 49 shows four oocytes in the uterus in 

 various stages of development ; in oocytes a and h one 

 sees the spermatozoa as short rod-shaped bodies, stained 

 black by the ha3matoxylin, lying in a dark area, stained 

 bi'ight red by eosin. Oocyte r shows the sperma nucleus 

 and the egg nucleus fusing in the same manner as described 

 by V. Janicki (1907) for the eggs of Ta3nia s errata. The 

 plasma of the eggs in these first stages after fertilisation is not 

 homogeneous, but contains larger and smaller masses of 

 differently staining substance. 



The later fate of the eggs has not been followed up; at 

 first, liowevei", the multiplication of the nuclei is not followed 

 by division of the plasma, so that up to four nuclei can be 

 seen in an undivided mass of plasma. Later on one observes 

 quite regularly that the cell division gives rise to a few 

 macromeres, and to a greater number of micromeres, the 

 macromeres probably giving rise to the egg envelopes, the 

 micromeres to the embryo, as demonstrated by Janicki 

 (1907) for Tajnia serrata. The exact number of macro- 

 meres is difficult to ascertain accurately: one is always larger 

 than the others ; two can usually be recognised, but I am 

 not certain whether there is a third or no. 



Soon after the eggs arrive in the uterus they become 



