380 



44 



no knowledge of the appearance and mode of growth of the plant in the living 

 condition; but in advance I am most inclined to believe that Mme. Weiseh van 

 Bosse is right in considering it as a variety of the comprehensive Caiilerpa 

 racemosa. 



With regard to my West Indian forms of var. clavifera and var. uvifera they 

 are all to be considered as rock and coral-reef forms, growing generally in quite 

 shallow water often rather exposed to the swell and in intense light. Svedei.ius 

 who, judging from his figure 15 has had a rather typical form of var. uvifera 

 (nevertheless it seems also to be rather near var. occidentalis, cfr. Svedelius p. 130), 

 tries in various ways to show differences between the two forms. Thus he writes 

 (pag. 122): "What constitutes the main difference between the clavifera and the 

 uvifera series is that in the latter (Fig. 15) the vertical axes (assimilators Reinke) 



reach a higher degree of 

 development, while at the 

 same time they are not 

 so close. They are, as 

 a rule, somewhat longer 

 and have more numerous 

 ^^ extremely close branchlets, 

 which are situated around 

 the vertical main axis". 

 This is indeed quite in 

 accordance with my view 

 when we consider typi- 

 cally developed speci- 

 mens, but nevertheless 

 numerous specimens are 

 to be found which may 

 be called clavifera but have well developed erect shoots. The figure of Fucus 

 clavifer Turner has really also very well developed erect shoots. The main point 

 must be laid stress upon, as Svedelius also demonstrates that in var. uvifera the 

 ramuli are more closely placed, in var. clavifera more open. The forms delineated 

 here (Fig. 22 and 23) of var. uvifera I therefore do not consider as specially typical 

 even if the assimilators are very well developed, the ramuli being rather openly 

 placed, and further it had very densely placed assimilators, growing as it did in 

 a rather compact tuft. 



Svedelius then looks for a difference in the root-system between the var. 

 uvifera and var. clavifera; the first one is said to have a very strongly developed 

 root-system, the last mentioned a feeble one and the reason for this is said to be 

 that var. uvifera grows in sand and mud, whereas var. clavifera is to be found on 

 stone and corals. But such a difference I have in no way found in my West Indian 

 forms, which all generally possess a very well developed root-system; in this con- 



Fig. 22. Caulerpa racemosa (Forsk.) Weber van Bosse 



var. uvifera (Turner) Weber van Bosse. 



From Longreef (St. Croix). (About 1 ; 1.) 



