43 379 



var. iwifera (Turner) Weber van Bosse, Monographie, p. 362. 



var. occidentalis (J. Ag.). Syn., C. Chemnitzia ß occidentalis J. Ag., Caulerpa p. 37. 

 SvEDELius, 1. c. p. 130. C. racemosa var. Chemnitzia, Reinke, 1. c. p. 38, 

 fig. 57. Exsicc. WiTTR. & NoRDST., Algæ exsicc. Nr. 1586. 



var. laetevirens Mont., Weber van Bosse, Monographie, p. 366. 



var. Lamourouxii (Turner) Weber van Bosse, Monographie, p. 368. 

 Before describing all the above-mentioned forms I may point out that what 

 I have said concerning C cupressoides holds good here also, namely, that in mj' 

 opinion it seems impossible to consider all the many varieties of this species as 

 separate species; I may thus quite follow the views of Mme. Weber van Bosse. 

 If one has a large material it will soon be evident that the different forms are 

 often united to such a degree by transitions that the boundaries can only be made 

 quite arbitrarily. 



It may willingly be granted that the forms which the older algologists con- 

 sidered as species really often seem very well defined. But the fact is that they 

 often had only some few sometimes perhaps only a single specimen to base their 

 species on. It is very often a description of individuals we find in their papers. 

 If we have a large material containing all these many variations, and when we 

 further have good reason to believe that these owe their existence for a great part 

 to the influence of external factors (experimental cultures may be decisive here, 

 we know onlj^ how variable C. proliféra can be under different conditions of life), 

 then it will soon prove to be impossible to maintain all these species. 



It is quite true that I have found in the same locality, even matted together 

 in the same tuft, the two varieties, namely var. occidentalis and a form of var. 

 iwifera which were thus growing together under quite the same external conditions 

 of life. This goes to show that these forms are rather fixed and that it might 

 therefore be right to consider these forms as separate species. But if we do so 

 and consider var. occidentalis as a separate species, what should we then do 

 with the intermediate forms, with which this form is united to var. clavifera and 

 var. iwifera and to var. laetevirens. I for my part cannot see any other conclusion 

 than that it is most natural, in accordance with the view of Mme. Weber van 

 Bosse, to consider all these many related forms as one species with manj' more 

 or less differentiated varieties. 



Thus, I believe that it is impossible in my West Indian material to consider 

 var. clavifera and var. uvifera as species, as Svedelius tries to make them, as these 

 forms in my material are very evenly connected with each other. Any specimen 

 quite in accordance with the typical var. uvifera (Turner, Fuci, fig. 230) and for 

 the rest like specimens from the Red Sea from where this form {Fucus racemosiis 

 Forsk.) was originally described, I have certainly not found in the Danish West 

 Indies. The typical form is surely a true sand Caulerpa most probably growing 

 in shallow water and in strong light; how far it would be most correct to consider 

 this the typical form as a particular species, I shall not try to explain here, having 



49* 



