54 



follov; no lav; of syrrnrtry, and T,ay coT:e. to lie in any nosit- 

 io-i. Figures IS, 16 and 17 shov; throe diffe:-ent forms 

 which the cells of the sixteen cell sta^e accuire, and 

 various other arran.c^e^ie-ts of the blastOTieres v;ere seen v/hile 

 studyi"? the livinp: eggs v/hich could not be figured for 

 wa-^t of snace. However the three figures are sufficient 

 to sho',7 that the general forrr, of the egg in this stage T.ay be 

 very different. In Figure 15 it is nossible to i-iagine a 

 direct relationshin to a nreceding for^- ,iust a little -lore 

 irrec^ular than is sho'.?^ in Figure 14. In a for-' as represen- 

 ted in Figure 16 the descent of the different cells frorii 

 the individual bla3t:"'eres of the eight cell stage is less 

 easily rccogrized. Firure 17 sht)Y,'S an egg in v.-hich all six- 

 teen blastomeres are spread out to frrir. a flat plate one 

 cell thiol; in the forr of a quadrangle, Cne can easily 

 conceive hov; this arrangement can have resulted frcni a 

 regular eight cell ::tage in vhich the rotation of the cells 

 of the one quartet vas greater thar that shcvn in Figure 



