132 STUDIES IN GENERAL PHYSIOLOGY 



upper surfaces of the lateral branches, and were therefore 

 directed, not toward the old, but toward the new tip of the 

 animal. Furthermore, the acute angle at which the new 

 lateral branches arose from the main stem opened toward the 

 zenith ; the convexity of the new branches was also directed 

 toward the zenith. In this way animals were therefore 

 formed which ended in a tip at both ends animals that were 

 biapical ; just as though one were to grow a new top upon a 

 tree in place of the roots, without, however, allowing the old 

 apex to go to pieces. In the specimens illustrated in this 

 paper the tips are still relatively small. My stay at Naples 

 was too short to allow me to wait for them to reach maturity. 



3. When stems of Aglaophenia which had been cut off 

 close to the roots, the tips of which, however, were left intact, 

 were suspended vertically and in an upright position in 

 water, a new root was invariably formed at the basal end, 

 and never a new tip. 



It therefore seems that the position of the stem of Aglao- 

 phenia determines to a certain extent whether a heteromor- 

 phosis, or only a regeneration, of the lost part occurs at the 

 basal cut end. 



4. This fact is further supported by the following obser- 

 vation : When stems of Aglaophenia from which the tips and 

 roots had been cut were suspended vertically in the aquarium 

 so that both cut ends were surrounded by water, a root was 

 always formed upon the end directed downward, it mattered 

 not whether it was the basal or apical end. 



In many cases branches were formed at the end directed 

 upward, yet in other cases a root was formed here also. A 

 root was formed most frequently upon the ends directed 

 upward when the basal end of the stem was pointed in that 

 direction; branches were formed most frequently when the 

 apical end of the stem was directed upward. 



It is therefore possible to create bi basal Aglaopheniae, 



