580 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Some Endophytic Algae.* — A. D. Cotton records some observations 

 on the life-history of Endoderma viride Lagerheim, and deals also with 

 two species of Streblonema, S. intestinum, and S. Zanardinii. The 

 plants of Endoderma studied by the author were endophytic in Nito- 

 phyllum Hillice, and in case future authors should regard this Endoderma 

 plant as distinct from the typical endophytic form in Derbesia, it is here 

 named f . Nitophylli. The vegetative structure is described, as well as 

 the formation of zoospores. The germinating spores are rarely seen on 

 N. Hillm, and the plant spreads very readily by a purely vegetative 

 method. No light is thrown on the difficult question of what becomes 

 of the spores during the winter. The growth of Endoderma viride f. 

 Nitophylli takes place entirely within the substance of the host-plant, 

 and there is no trace whatever of external branches or hairs. It is not 

 in any way parasitic. A list of species is given in which this endophyte 

 has been found. The original description of Streblonema intestinum 

 {Entonema Reinsch) being quite inadequate, a new description is here 

 given, based entirely on Reinsch's preparations. The species differs 

 from S. parasiticum Sauv., which occurs in Gystoclonium and Geramium 

 by the larger sporangia, and by the apparent absence of external fila- 

 ments. A short note on S. Zanardinii De Toni adds to our somewhat 

 scanty knowledge of the plant. The plurilocular sporangia are described, 

 and a bifurcating example is figured. 



On " Zoochlorella " in Convoluta.f— F. Keeble and F. W. Gamble 

 give a preliminary account (1) of experiments proving that the green cells 

 (zoochlorellge) of Convoluta roscoffensis result from infection from with- 

 out ; (2) of the means whereby the infecting organism may be cultivated 

 outside the body of the animal ; and (3) of the nature of the infecting 

 organism. A detailed account is given of the mature alga which, in 

 the opinion of the authors, belongs to Chlorophycese, and is allied to 

 Chlamydomonas. The presence of four equal flagella suggests that they 

 belong to the genus Carteria. 



Fossil Diatoms. J — A. M. Edwards reports on 16 samples of in- 

 fusorial earths containing diatoms sent to him by the United States 

 Geological Survey. They are interesting as coming from the great plain 

 of Fremont in Utah, Nevada and California, called by the author the 

 Occidental Sea. Lists of species found in each of the samples are given. 

 The author makes some remarks on the geology of the tract examined. 

 He maintains that the lakes Bonneville and Lahontain were formed in 

 the earlier Tertiary, possibly the Eocene or the Cretaceous, and that the 

 " infusorial earth," which is clayey, was formed before the clay Oligocene 

 of California from Monterey, Redondo Beach, etc. The infusorial clay 

 of the Great Plain constitutes the bed of an extinct sea, the Occidental 

 sea. 



North Atlantic Plankton.§ — C. H. Ostenfeld publishes a catalogue 

 of the species of plants and animals observed in the plankton collected 

 during periodical expeditions from August 1902 to May 1905, under- 



* Journ. Linn. Soc. Bot., xxxvii. pp. 288-97 (1 pi.). 



t Proc. Roy. Soc, Series B, lxxvii. (1905) No. B 514, pp. 66-8. 



X Nuov. Notar , xvii. (1906) pp. 102-7. 



§ Copenhagen : Hoest et fils, 1906, 122 pp. 



