184 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



14. It is concluded from these data that it is a certain 

 similarity between adjacent colonies that determines that 

 they shall not remain separate and compete with one another 

 but shall fuse. 



15. In fusing, the ampuUce of one or both adjacent colo- 

 nies penetrate the test of the other and fuse with its vessels. 

 Two ampullae never fuse. 



16. Zooids from two fused colonies may unite to form 

 the same system. 



17. The zooids in both parts of a fused colony become 

 perfectly coordinated so far as growth and reproduction are 

 concerned. 



18. On the whole, the colony of Botryllus and Botrylloides 

 must be considered as a single and not as a composite indi- 

 vidual. It cannot be considered as merely the sum of its 

 constituent zooids. 



University of California, 

 Berkeley, California, 

 June ir, 1901. 



