37 



the parent polyp had no bud on it. Threo days afterward a 

 small creature v/as found upon a spot which had been cer- 

 tainly unoccupied by any larva up to that time, careful di- 

 agrams having been made as stated above. This was a larva 

 like that in figure 23. It v^as measured, and although 

 changed in shape, as nearly as one could estimate its bulk 

 it cori-esponded exactly with the bud which had disappeared. 

 Similar experiences were repeated so many times that it 

 seemed unavoidable to consider this a normal phase in the 

 process. This being so, it is an interesting case of re- 

 version in the non-sexually developed larva to a condition 

 earlier in point of ontogenetic order than that in which the 

 parent v/as when it gave rise to the bud. In any case, the 

 future history of the bud is certain. After settling down 

 upon the bottom, it repeats the changes which occur in the 

 sexually produced polyp. The newly arisen larva (Fig, 22) 

 loses its planula shape, becoming shorter and thicker, es- 

 pecially at the base, on account of the plastic character 

 of the tissues (Fig. 23), It has now secured a firm hold 

 upon the bottom, being so closely applied to it that it can 

 be dislodged with difficulty. The cells at the base in- 

 crease in thickness until they form a columnar epithelium 



