ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 739 



d'Emilia). The full paper is destined to appear in the transactions of 

 the Reale Istituto Veneto. The great part of the deposit investigated 

 is constituted of characteristic fragments of Coscinodisc us Gazethr .Jan. 

 The list contains eight Raphideae, four Pseudoraphideae, sixty-five 

 Cryptoraphideae. 



Genus Micrasterias in New England.* — J. A. Cushman publishes 

 a synopsis of the New England species of Micrasterias, twenty-two in 

 number, and several varieties. Fourteen of these species occur in the 

 British Isles. The author gives a description with synonymy, refer- 

 ences, measurements, and notes under each species and variety, and 

 adds a key to aid in the identification of the species. 



Zygospores of Spirogyra in Relation to Theories of Variability.! 

 L. B. Walton has studied the zygospores of Spirogyra qvadrata to 

 obtain data as to the causes tending to produce variability. Over 

 400 zygospores were studied, including those formed by scalariform 

 and by lateral conjugation. Scalariform conjugation yields the products 

 of union between remotely related cells belonging to different filaments. 

 Lateral conjugation gives the results of union between sister or adjacent 

 cells of the same filament. According to AVeisemann the former case 

 should favour variability of offspring, and the latter case should afford 

 a decreased variability. Walton's studies, however, yielded results 

 directly contrary to this theory ; for the zygospores of lateral conjuga- 

 tion were about 21 p.c. more variable, both in length and in breadth, 

 than those of scalariform origin. Support is thereby given to the 

 theory of Hatschek (1887) that sex exists for the purpose of limiting 

 and not for the purpose of increasing variability. 



Index of Desmidese.^ — 0. F. 0. Nordstedt issues a supplement 

 to his Index Desmidiacearum, which was published in 1896. Much 



material having accumulated since that date, a large supplement became 

 necessary. The new bibliography provided cites about 500 papers by 

 120 authors. 



Fresh-water Algae of Java.§ — C. Bernard publishes an illustrated 

 account of the Protococcaceae and Desmidieas gathered by him in fresh- 

 water at Buitenzorg and some other localities in Java. Finding that 

 the literature previously published was insufficient to enable him to 

 determine all the specimens he collected, he set to work and figured his 

 specimens and described all the novelties himself. He gives a list of 

 326 species and varieties, and illustrates them with 580 figures. He 

 describes two new genera : Stein id In and Treubaria, and 87 new species 

 and varieties, and makes numerous additions to the Javan flora. He 

 appends a bibliography of ninety-three works, and sketches briefly the 

 condition in which he found the fresh -water algology of Java. In other 

 chapters he discusses his methods, the variability of the organisms, their 



* Rhodora, x. (1908) pp. 97-111. t Torreya, viii. (1908) p. 228. 



X Index Desmidiacearum. Supplementum. Berlin : Gebr. Borntraeger, 1908, 

 150 pp. 



§ Protococcacees et Desmidiees d'eau douce recoltees a Java. Dept. de 1' Agri- 

 culture, Batavia, 1908, 230 pp. (1G pis.). 



