THE CEYLON SPECIES OF CAULERPA. 123 



on the beach, washed ashore probably from somewhat deeper regions. It is also remarkable that in 

 regard to the root-system quite a remarkable difference prevails between C. racemosa and C. uvifera. 

 The latter has, as can easily be seen by comparing figs. 13, 14, and 15 a much more richly developed 

 root-system. 



The root branches are longer and more branched, parting into innumerable fine root-branchlets. 

 These adhere so firmly to sand and shell particles that on uprooting these plants masses of sand 

 and the like will loosen and accompany the roots sooner than these latter break. The davifera, preferably 

 growing on corals and stones, on the other hand, has not by a long way so finely branched a root-system, 

 but is fixed by few and coarser root-branchlets. 



The difference that exists between C. racemosa and C. uvifera in respect to their organization 

 corresponds therefore with different localities. The majority of Ceylon forms of wi^j/era observed by me 

 seem to belong to /. intermedia (Weber v. Bosse), at least when chief importance is laid on the charac- 

 ter which is laid stress on in the diagnosis, viz., that " les ramules " are evidently stalked. 



The /. com,'pressa Weber v. Bosse (Harvey, Ceylon Algae 63) I have been unable to find again. 

 On the other hand, in the Peradeniya Herbarium there is a little form from Bentota labelled " C. sedoides 

 Ag. " which seems indentical with Harvey's C.A. 63. Probably it is a mere accidental form, which 

 does not play any very important part in the vegetation. 



Fig. 16. — C. uvifera (txjkneb Fig. 17. — C. uvifera (tubnek.) /. planiuscula n. f. 



f. planiuscula n. /. (1 x 1). Different kinds of branchlets — a, b, c from the 



base, d, e from the top. (3x1). 



The /. 'planiuscula is of a great theoretical interest. Fig. 16 shows a picture of it. Weber v. 

 BosSB has, in her monograph figured such a form {loc. cit. PI. XXXIII. fig. 24 a and b. ) and also described 

 its origination, though only in the explanatory text accompanying the figure (p. 401, &c), without, 

 however, giving it a special name and only arranging it under /. intermedia. She does not mention it in 

 deahng with the different forms of C. uvifera. As to the mode of growth and habit, it corresponds with 

 other uvifera forms. On a closer examination of the axis, however, we shall find that, especially 

 at the point, flattened out vesicles occur together with transition- stages to the spherical ones 

 (fig. 17). Such branches remind one somewhat of C. peltata and C. Chemnitzia, but from these the 

 /. planiuscula differs partly by the lack of cyUndrical branchlets at the base, partly too by the flattened 

 branchlets being more sharply distinguished — the vesicle being more distinctly set of from the stalk and 

 not with the shape characteristic of Chemnitzia. The organisation of f .planiuscula means, as we can see, a 

 certain increase of the assimilating surface, in analogy with C. peltata and C. Chemnitzia. But whereas, 

 as for instance in Chemnitzia , the flattened branchlets are derived from strictly cyhndi'ical branchlets, 

 in f . planiuscula they are formed by transformation of spherical branchlets (cf. fig. 17). These different 

 forms consequently show a fine example of how forms externally similar may be developed in different 

 ways. 



