PLATE IV. 



lieio'é ovata. XGO, 

 X X ill sürui! of tlio tigures in this plate indicate the bottom of cleavage furrow at 

 the time of operation. 



Fig- 47- Egg partially cut in two liorizontally, a little above the " head " Ü.45 PM. 



Fig. 48- The same. 2 PM. 



Fig- 49- Ego an which young " head " has been split lengthwise by a vertical 



incision. 9.55 AM. 

 Fig. 50- The same 11.35 AM. 

 Fig. 51- Operation similar to Fig. 49. The '' head " had got halfway when cut. 



11.15 AM. 

 Fig. 52- The same. 1 1.35 AM. The cleavage furrow cut through the egg at 0.5 PM. 

 Fiö". 53. Egg with two cuts, one longitudinal and the other horizontal, separating 



nucleated portion from right-hand prominence. 10.29 AM. 

 Fig. 54. The same. 11.24 AM. 

 Fig- 55- Egg from which a portion of cytoplasm has been cut off and the " head " 



split lengthwise. 11.15 AM. 

 Fig- 56- The same. 11.55 AM. 

 Fig- 57- Egg operated on similarly to Fig. 55. 

 Fig. 58- Cleavage furrow has been formed from the bottom of the cut towards the 



left. 

 Fig. 59- Cleavage furrow has cut through the egg. Nucleated portions of both the 



blastomeres have divided. 

 Fig- 60- Egg in which the " head " has been split lengthwise and an incision made 



at the micromere pole. 9.42 AM. 

 Fig. 61. The same. 10.40 AM. 

 Fig. 62- The same. Cleavage furrow has cut through the egg, forming an enucleated 



mass on the right. 



