F. Børgesen: The Species of Sargassum. 17 



Nevertheless, there are some few statements to the effect, that growth of the floating 

 Sargasso does take place. So for instance Krummel writes (Peterm. Mitt., 37. Bd., 

 1891, p. 135): "Unser Botaniker (of the German Plankton-Expedition), Hr. Dr. F. 

 ScHtJTT, stellte fest, das die Pflanze lebten und tiberdies ein gewisses, wenn auch ge- 

 ringes Wachstum zeigten." And Bouvier (Bulletin de l'Institut Océanographique, 

 Monaco, 1907, No. 93, p. 35) says: 



"On sait que les Sargasses å flotteurs (Sargassum hacciferum) végétent au voisinage des 

 cotes américaines tropicales å la maniére de nos Fucus, et que les portions detachées de leurs 

 thalles, entrainées par les courants, viennent se réunir dans un vaste espace de 200,000 kilo- 

 metres carrés, compris entre le Gulf-Stream et le courant équatorial. A lui seul, eet apport 

 serait insuffisant pour peupler d'Algues une étendue aussi vaste; mais, si les Sargasses flottantes 

 ue forment aucun element reproducteur, elles végétent parfaitement å la surface des flots, y pous- 

 sent des rameaux, des expansions foliacées et des flotteurs, sans doute également s'y divisent 

 sous l'influence des vagues, chacune de leurs branches detachées donnant naissance å une toufie 

 nouvelle." 



Gran in "The Depths of the Ocean", 1912, p. 336, writes: "The Sargasso weed 

 continues to grow as it drifts, but the gas-bladders are not formed in the same pro- 

 portion as on the ordinary branches ..." To this last remark I may point out, 

 that in my material, I have found quite as many gas-bladders in development in 

 the young parts of the branches as in the older parts; moreover, in this connection, 

 may be stated that the gas-bladders "in-toto" are proportionally much more numerous 

 in the pelagic floating forms than in the attached forms at the shores. 



A second question, and of no small importance is: where did the floating 

 Sargasso originale? 



Although the present writer agrees in all respecsts with Harvey (comp. p. 15), 

 that the Sargasso has lived for ages in the Sargasso Sea, yet it seems possible that 

 the floating Sargasso was originally derived from detached forms; furthermore I venture, 

 to express the opinion that renewed increase in this way may take place the day 

 to day. ^) 



But the question about the origin is however difficult to settle, and before I make 

 any attempt to solve the problem, I wish to give some introductory remarks upon 

 Sargassum natans and detached algæ on the whole. 



ebenso darf man die auf hoher See schwimmenden Sargassum-Fragmente nicht pelagische Pflanzen 

 bezeichnen". By means of seven "reasons" this author, at last, reduces the floating Sargassum 

 in the Sargasso Sea to "schwimmenden 6'argassMm-Fragmente". Compare also Kuntze in his Revisio 

 generum plantarum, Part II, 1891, p. 915. 



However Otto Kuntze does deserve credit for having compiled a good deal of the very 

 comprehensive litterature upon this subject. 



') The supposition offered by Piccone, according to Forbes, that the Sargasso constitutes a 

 proof of the sunk Atlantis (fide Sauvageau, 1. c.) appears to me much too hazardous. 



3 



