138 



where the conditions of hfe are so very different, that we find the 

 types of alga round which the remaining forms group themselves 

 in a natural way. 



Several of the forms which occur at each of these different 

 localities may by themselves be very diverse, so that one could 

 perhaps entertain doubts whether it w^as not most correct to con- 

 sider them as separate species; but on the other hand, they are 



Fig. 108. Caulerpa cupressoides (Vahl) Ag. 



var. mnmillosa (Mont.) Weber-van Bosse. 



From shallow water. OfT Longford (St. 



Croix). (About 1:1). 



Fig. 109. Caulerpa cupressoides 

 (Vahl) Ag. var. typica Weber- 

 van Bosse. In shallow water. 

 Protestant Cay lat Christians- 

 sted). (About 1:1). 



commonly so connected with intermediate forms, often the same 

 specimen shows so considerable variation in the one or other direc- 

 tion, that it seems to me until further information is obtained 

 most natural to keep them together. We can only settle the 

 matter definitely by the help of culture experiments, e. g. trans- 

 plant specimens from exposed to sheltered localities and vice- 

 versa, an experiment which would surely not be difficult in prac- 

 tice. Should it then appear that a certain form even after having 



