70 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Algae of the West Indies, Indian and Pacific Oceans.* — N. Svedelius 

 deals with the interesting subject of the likeness between the marine 

 flora of the West Indies, the East Indies, and the Pacific. He disapproves 

 of the theory that the Cape of Good Hope had formerly a more tropical 

 climate and served as a passageway for algaj. From a careful study of 

 Gaulerim and other genera in the Indian Ocean he is led to the belief 

 that the Caribbean Sea was at one time in connection with the Pacific 

 Ocean and was only separated at a later date by the upheaval of land 

 at the isthnuis of Panama. 



AigaB of a Ceylon Coral Reef.f — N. SvedeUus has made a careful 

 study of the algae on the large coral reef which surrounds the town at 

 Point de Galle, Ceylon. His object was to discover if in the tropics 

 there is any periodicity of marine algae, and his investigations have led 

 him to the following interesting and important results. He finds that 

 a rich, purely littoral flora may occur in the tropics, a fact which has 

 been somewhat doubted hitherto. Certain conditions are of course 

 necessary, such as for instance an absence of predominating living coral, 

 as this prevents the growth of algae other than those with a strong 

 creeping rhizome. Further, he finds that the Floridete are more numer- 

 ous both as regards species and number of individuals than the other 

 algas-groups, notwithstanding the strong light. Tlie littoral Florideee 

 have not pure red chromophyll, but rather a dark violet, grey-brown, 

 and grey-green tone of colour. As regards periodicity in the algae he 

 finds this quite a marked feature : certain short-lived species such as 

 Porphyra suhorhicnJafa and Dermonema ilirhotonium, only occur during 

 a particular part of the year ; other species are perennial, arising either 

 from a basal disc or from basal holdfasts, which persist, while the upper 

 part of the thallus bears new shoots season by season : — examples being 

 Laurencia ceylanka, Rhodomela crassicauUs, Sargassum cristcefolwm, and 

 AvrainviUea lacerata. Again certain species show their periodicity by 

 becoming fertile at special seasons of the year. In many instances 

 periodicity is connected with the change of monsoon, some species 

 appearing only after the south-west monsoon has been blowing for 

 some time, while others choose this time for dropping and regrowing 

 their shoots. In what way the monsoon influences the plants is not 

 known at present, though several theories are put forward. Finally the 

 author states that short-lived species are very few, while the great mass 

 of species are perennial and bear during the whole year the most intense 

 sunlight. Two photographs show a formation of Rhodomela crassicavlis 

 and CoraUopsis Opuntia respectively. 



Vegetation of the Antarctic Sea. J — C. Skottsberg, the official 

 botanist to the Swedish Antarctic Expedition, has published his obser- 

 vations on the marine flora of this region. The main bulk of his 

 collections were unfortunately lost with the ship, but sufficient were 

 saved to enable the author to give a fuller account of the conditions 

 affecting the algae, and the species growing or collected there, than 



* Bot. Notiser., 1906, pp. 49-57. 



t Botaniska Studier. Tillagnade: F. R. Kjellman, 1906, pp. 184-220 (1 pi.). 



X Tom. cit., pp. 245-64 (3 pis. and 1 map). 



