ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 333 



found in a swamp in April, and was accompanied by other Volvocacese ; 

 in California it occurs in June. The author describes the life-history, 

 morphology, asexual multiplication, cytology. The plant is nearly 

 related to Eadorina, but differs in the fact that all its individuals are 

 germinocytes. The author treats of the differentiation of the soma 

 and the germen, and sundry other matters, such as the Sponges and 

 Choaneflagellates, the phylogenetic significance of the spermatozoid, 

 which in its simplest form would be a protomonad with an inherited 

 power of movement, the flagellum situated behind it. 



Antarctic Algae.* — W. and G. S. West report on the fresh- water 

 algse collected by the British Antarctic Expedition led by E. H. Shackle- 

 ton in 1907-9. The number of species enumerated is eighty-four. No 

 Conjugate were collected. The Myxophyceae were the most frequent. 

 The Diatomacete were very numerous in some of the lakes. There was 

 a conspicuous absence of Eed or Yellow Snow in the region visited. 

 The water of Clreen Lake is very saUne, and yet contains a great number 

 of algte regarded as proper to fresh-water, and also many marine diatoms. 

 A brief account of the seventeen gatherings is given, and is followed by 

 a systematic account of the species observed, among which the novelties 

 are twenty-two species and five varieties. 



Nuclear Structure of Closterium.t — C. von Wisselingh writes on 

 the nuclear structure and karyokinesis of Closteriuni Ehrenbergii. As 

 regards the nucleoli, he finds that they do not correspond with those of 

 Spirogyra, but with those of the higher plants. They are present in 

 considerable number, forming a conglomerate in the middle of the 

 nucleus. The nucleus normally divides by mitosis. Some peculiarities 

 are the distrilnition of the nucleoli in the nucleus, their ejection into the 

 cytoplasm, the large flat nuclear plates, and the large number (more 

 than sixty) of the chromosomes. The chromosomes are usually short 

 and of irregular length. The nuclear spindle is elongate, and not 

 strongly developed. The daughter-nuclei travel along the cell-wall. 



Spanish Diatoms.^ — J. Gamundi y Ballester publishes a list of the 

 diatoms of Santiago de Compostela and its environs. They are partly 

 new to the Spanish flora, partly interesting species ; and one of them, 

 Amphipleura Lindheimeri Grun. var. Truani Van Heurck, photographs 

 of which are given, had not previously been met with in Europe. The 

 list contains fifty-six species and varieties. 



Navicula socialis.§ — T. C. Palmer continues his observations on 

 Navkula socialis. He confirms his previous conclusions that the 

 grouping into blocks of four is a constant and essential characteristic. 

 Also he finds that redupUcation within the group is simultaneous, 

 the frustules of a given group being all of the same size, though the 

 length of the group may vary from 120 /x down to 60 /x. Another 



* Shackleton, Brit. Antarct. Exped. Rep., i. (1911) pp. 263-98 (3 pis.). 



t Versl. Kong. Ak. Wet. Amsterdam (1910) pp. 170-81. 



J;Bo1. R. Soc. Espafiola Hist. Nat., xi (1911) pp. 888-9-4 (1 pi.). 



§ Proc. Delaware Co. Inst. Sci., vi. (1911) pp. 115-20. 



