ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 73 



can develop. A new species, Carter ia ovata, can be cultivated on 

 organic salts of calcium, etc. The occurrence of these alga; must be 

 very common. They are all very sensitive to acids, but less so to alkalis. 

 By their capacity to produce a great amount of oxygen they markedly 

 assist in the purification of dirty water. The cultivated Volvocaceag 

 are strongly sensitive to light, and show both positive and negative 

 phototactic reaction, according to the intensity of light and according to 

 their response to it, a thing which is influenced by different factors. By 

 means of this phototactic property and by means of their different be- 

 haviour when dried, one can separate the species from one another up to 

 a certain degree, and purify them from bacteria. The majority of them 

 can be bred pure by the usual bacteriological methods, since they form 

 colonies on solid nutritive substances. For their organic nutrition the 

 most important factors are the decomposition-products of albumen under 

 the action of trypsin ; for Carter ia ovata the organic salts of calcium 

 suffice. The algfe mentioned belong to the markedly myxotrophic 

 organisms ; but Fohjtoma uvella is an exception, being purely sapro- 

 phytic. 



Algse of Tyrol.* — F. Hustedt gives an account of the Desmidiacea3 

 and Bacillariaceffi of Tyrol, as a contribution to a knowledge of the algal 

 flora of the European High Alps. The specimens, preserved in formalin 

 or osmic acid, were collected by J. Traunsteiner in numerous localities, 

 and contained 217 forms, belonging to 2'd genera and 171 species ; and 

 among them are some eight forms new to science, and several which are 

 new to Tyrol. 



Algal Flora of Bremen.f — F. Hustedt gives an account of the 

 Bacillariaceae of the river Wumme, a contribution to the algal-flora of 

 Bremen. He enumerates 294 forms, comprising 37 genera and 187 

 species, and adds notes on questions of variation of form, biology, mor- 

 phology, etc. 



Littoral Diatoms of Japan. | — K. Okamura gives an enumeration of 

 some littoral Diatoms of Japan. They were collected chiefly on the 

 coast of Prov. Boshyu, near the entrance to the Gulf of Tokyo, mostly 

 in early summer during several years. Every species is figured. The 

 difficulty of obtaining access to literature on Diatoms is very great in 

 Japan. The author gives a list of papers consulted. Tn all he figures 

 fifty-seven species, several of them from five or six points of view. 



Development of Laminaria § — K. Killian gives an account of the 

 development of Laminaria di'jitata. 1. The swarm-spore produces a 

 few-celled germinating filament, some of the cells of which produce 

 secondary outgrowths, which first undergo an embryonal development 

 which is characterized by abundant cell-division in all directions. It is 

 only later on that a differentiation of tissues is initiated. 2. All tissues 

 stand in genetic connexion with one another, the internal being developed 



* Archiv f. Hvdrobiol. und Plantonk., vi. (1911) pp. 307-4G. 



t Abb. Nat. Ver. Bremen, xx. (1911) pp. 257-315 (2 pis. and figs.), 



i Rep. Imper. Fisheries Inst. Tokyo, vii. No. 4 (1911) 18 pp. (6 pis.). 



§ Zeitscbr. Bot., iii. (1911) pp. 433-94 (figs.). 



