634 WILSON. 



PLATE XXXVI. 

 [All from preparations and the cell-connections hypothetical, except in Figs. 113, 1 14 ; 350 diameters.] 



Fig. 103. Half-sized 8-celled stage, from isolated ^ blastomere, exactly equal 

 type. The other twin (enclosed in the same membrane) is unequal, like Fig. 104. 



Figs. 104, 105. Half-sized 8-celled stages, with last. Unequal type. Fig. 105 

 shows spindles of following division. 



Fig. 106. Double 2-celled stage, showing the effects of displacement in the 

 single 2-celled stage. 



Fig. 107. Double 2-celled stage (in division). Axes of the twin embryos at 

 right angles. 



Fig. 108. Double 4-celled stage, transitional form. The left side, as in the 

 normal entire ovum ; the right side shows the double form. 



Fig. 109. Double 4-celled form with slight obliquity of the axes. 



Fig. II o. Double 4-celled form with parallel axes. 



Fig. III. Double 8-celled form with oblique axes. 



Fig. 112. Transition from normal i6-celled form to double 8-celled form. 



Fig. 113. Double 4-celled form (transition to double 8-celled) showing remin- 

 iscence of the normal form of cleavage in the lower right hand fourth. 



Fig. 114. Individual of similar type. Nearly normal form of cleavage in the 

 upper half of each twin, double form in the lower half of each. 



