1093], 



ON CAVLERPA ANGEPS, HABV. 



155 



xi. 



stolons. The old parts of the stolons are almost always naked but provided 

 with number of scars, apparently wart-Hke processes, which must have been 

 the pedicels of the thick winter fronds. 



The alternative change of the form regularly 

 takes place at Misaki. But in the other localities 

 the rule seems to be little modified according to 

 the climate and the conditions of the place where 

 the plant grows. Those plants collected at Suno- 

 saki in December were quite similar with those 

 collected at Misaki in October : those at Shio- 

 misaki in April were entirely wanting of the 

 serrature and had the fronds lineari-spathulate. 

 The specimens collected in a high tide pool at 

 Tateyama, near Sunosaki, in December had the 

 serrature quite obscure and the frond robust — 

 the typical form of G. hr achy pus. 



These facts lead us to believe that the 

 seasonal dimorphism in a sense might occur in 

 Caulerpa. The season only, however, is not 

 the factor to cause the change, but the condi- 

 tions of the environs have also some influence 

 upon it. This is proved by the case of Tate- 

 yama. 



C. anceps, C. hrachypus, and C. Stahlii are 

 closely related to one another. The principal 

 characters to distinguish them, with those 

 grouped in the section Pliyllantoidece J. Ag., 

 as formerly remarked, lie on the proHferation, 

 the serrature, the thickness and shape of the 

 fronds. These characters are highly variable 

 and by no means serviceable to separate the 

 species, as Weber v. Bosse has already men- 

 tionedif*' The three species above mentioned 

 which are separated by the slight differences of 

 these characters become naturally doubtful. 



A special character of our plant seems to 

 have been overlooked by the former observers 



1. Mon. d. Caul. p. 277. 



