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361 



be in sheltered places, and, of course, especially at considerable depths that are not 

 disturbed by heavy sea". It is quite correct that Caulerpa proliféra often grows in 

 rather deep water where there is complete quiet; but it can live even in the 

 Mediterranean in rather exposed places. Janse tells us on the next page (I.e. j). 167) 

 how C. proliféra had distributed itself in recent years since the investigations by 

 Berthold over the eastern part of the gulf of Naples. He connects this with the 

 fact, that C. proliféra in exposed localities has a great tendency to be proliferous, 

 which means that C. proliféra has a method of propagating by means of its leaves. 

 He writes: "In wie weit die Eigen- "* 



scliaft der Blätter, neue Organe 

 bilden zu können, dabei von Ein- 

 fluss gewesen sein muss, geht wohl 

 schon ohne Weiteres aus dem Um- 

 stände hervor, dass die Stelle, wo 

 sich der Rasen befindet, in keinerlei 

 Weise durch davor liegende Inseln 

 oder Halbinseln geschützt ist, wie 

 dieses an vielen Stellen im Golf 

 von Pozzuoli der Fall ist, sondern 

 überall der durch Stürme hervor- 

 gerufenen, zumal im Frühjahr öfters 

 sehr starken Bewegung des Wassers 

 direct ausgesetzt ist. So lange Cau- 

 lerpa sich also im ruhigen Wasser 

 befand, war die Verbreitung eine 

 langsame, im stark bewegten Theil 

 des Golfes verbreitete sie sich aber 

 sehr schnell." From this descrip- 

 tion it follows that this alga must 

 grow in even very exposed local- 

 ities. The observations of Janse 

 agree very well with what is to be 

 found in the West Indies, where as mentioned above Caulerpa proliféra in deep 

 water has a broad leaf which is only very little proliferous, often not at all, in 

 shallow water on the contrary, where we have some surf, Caulerpa proliféra has a 

 narrow leaf which is very richly proliferous. 



Besides the two forms mentioned above, I have also found some few specimens 

 whose leaves were I'/a cm. broad and 17 cm. long and thus on the whole rather 

 like the common European form; in its more leathery consistency it was however 

 somewhat different. This form was found at White Bay on the south side of 

 St. Croix in about half a meter of water on a rather exposed coast. 



Caulerpa proliféra is rather common on the shores of Danish West India. 



I>. K. I), VidensU. Seisk. Skr. 7. Række, naturvidensk. og mathem. Afd. IV. 5. 47 



Fig. G. Caulerpa proliféra (Forsk.) Lam. f. zosterifolia n. f. 

 From the lagoon of Krause, St. Croix. (About 1 ; 1.) 



