76 SUMMARY OF CURRENT RESEARCHES RELATING TO 



the algae of the Indian Ocean, the author gives a list of areas the algae 

 of which are well known, insufficiently known, and slightly or not at all 

 known, appending the titles of the more important papers, geographi- 

 cally arranged. The unknown areas are the Mozambique Coast, 

 Delagoa Bay, much of the Indian Coast, Persian Gulf, and many 

 small islands. The present paper fills in some of the gaps in treating 

 of the islands of Diego Garcia and Mahe. In studying the algal 

 distribution in the Indian or any other ocean, it is essential to have an 

 accurate knowledge of the various ocean-currents — the most important 

 factor in their distribution, carrying not only those species which float by 

 means of air- vesicles, but also species parasitic upon them and the spores 

 of many other species. The main currents in the Indian Ocean are as 

 follows : South of the equator flows the great equatorial current from 

 east to west, which upon striking the north point of Madagascar splits 

 into two branches — the Agulhas and the Mascarene currents. The 

 latter flows south, while the former, passing round west of Madagascar 

 and sending out a small branch northwards, flows down the east coast of 

 Africa. This warm Agulhas current is met south-east of the Cape of 

 Good Hope (in about 40° S. lat.) by cold antarctic currents which 

 deflect it to the east where it joins up again with the Mascarene 

 current, and these united flow across to Cape Leeuwin, in West 

 Australia, accompanied by cold currents on the southward side. At 

 Cape Leeuwin a portion of this warm current, turning northward, 

 unites again with the equatorial current, thus completing its circuit. 

 Another and less important current runs south of the equator, but 

 north of the aforesaid equatorial current and in the contrary direction — 

 namely, from west to east. By the help of the above currents there is a 

 possible means of communication between the marine floras of the 

 Malay Archipelago and West Australia and those of the Mascarenes 

 and Madagascar, as well as of the east coast of Africa. 



The rest of the paper is devoted to a consideration of the character 

 of the algal flora of the Indian Ocean. Taken as a whole it does not 

 appear to have any very distinctive flora of its own. In the southern 

 parts the character is that of the subantarctic zone. As regards the 

 tropical parts the west and north have a fairly uniform character, but 

 the east exhibits signs of the influence of West and North Australia 

 and of the Pacific Ocean. 



Bocat, L. — Sur la Marennine de la Diatomee bleue; comparaison avec la Phyco- 

 cyanine. (On the Marennin of the blue diatom : comparison with Phycocyanin.) 

 [A chemical analysis of the blue coloration of Navicula ostrearia, designated 

 by E. Ray Lankester as Marennin.] 



C.R. Soc. Biol. Paris, lxii. (1907) pp. 1073-5. 



Duggar, B. M. — The Relation of certain Marine Algae to various Solutions. 

 [Plasmolytic experiments with various isosmotic solutions of sodium chloride, 

 potassium nitrate, and sugar ; also the poisonous action of certain salts 

 of the alkalies and alkaline earths upon marine algae.] 



Trans. Acad. Sci. St. Louis, xvi. (1906) pp. 473-89. 



Edwards, A.M. — The so-oalled "Infusorial Earths," and their Chemical Analyses. 



Chemical News, xcv. (1907) pp. 241-5. 



Mazza, A. — Saggio di Algologia oceanica. (Contributions to marine algology.) 

 [A continuation.] Nuov. Notar., xviii. (1907) pp. 177-95. 



