ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 507 



Fossil Diatoms.* — A. Lauby publishes an important work on the 

 palfeophytology of the volcanic regions of Central France, where he has 

 discovered new stations rich in plants of the Tertiary period. Besides 

 working out the higher plants, the author has made a special study of 

 the diatoms. The species and varieties of the different strata are dis- 

 cussed, and their relationship to modern species, as well as their more or 

 less long succession in the series of the different geological periods. The 

 species recorded number 585 and the varieties 312. Forty species are 

 new. In a discussion on the modification of tertiary diatoms due to the 

 influence of environment, the author shows that the morphological 

 characters are in certain species altered according to the degree of 

 salinity of the water in which they have developed, while other less 

 resisting forms have disappeared after a certain time. He is of opinion 

 that a large number of related forms are merely successive stages of 

 evolution in modified species, and he points out the links which exist 

 between fossil and modern types, showing the intermediate progression. 

 He therefore doubts the value of many of the present day " species." 



Didymosporangium.t — F. D. Lambert describes a new genus and 

 species, Didymosporangium repens, belonging to Ch^etophoracese, which 

 he found growing epiphytically on Antithamnion Plumula at Naples. 

 It is filamentous, slightly branched, with intercalary sporangia containing 

 four spores. 



Morphology of Dictyosphseria.J — AV. Arnoldi has made an ex- 

 haustive study of the structure of Dictyosphderia, two species of which he 

 has collected himself on the coral reefs of the Malay Archipelago. 

 After describing each species separately and in detail, he gives a general 

 account of the structure of the protoplast, and the reproduction. 

 Finally, he discusses shortly the views of Derschau and of Lewitski on 

 the origin of chromatophores from mitochondia. He believes himself 

 in a connexion between nucleus and pyrenoids ; and holds that under 

 the name mitochondria the most different bodies have been included, 

 utterly unlike, both in origin and function. 



Embryogeny of some Fucaceae.§ — M. Tahara continues his studies 

 on Japanese Fucaceae, and publishes his results. In a previous paper he 

 gave the opinion that a simultaneous liberation of oospheres (a term he 

 changes in the present paper to oogonia) took place fortnightly at a 

 fixed interval after the highest spring-tide, the interval varying in dif- 

 ferent species. In order to confirm this statement he renewed his 

 investigations on Sargassum enerve, S. Homeric and Cystophyllum sisym- 

 drioides. He found that a general oogonium-li Deration of S. enerve^ 

 occurred on the day following the highest spring- tide, and three days 

 later the same phenomenon occurred in S. Horner i. But the subsequent 

 liberation went on, irrespective of relation to the highest tides, though 



* Bull. Carte Geolog. France, No. 125 (1910) 393 pp. (15 pis. and 53 figs.). See 

 also Nuov. Notar., xxiv. (1913) p. 149. 



t Tufts College Studies, iii. (1912) pp. 111-15 (pi.). 



X Mora, V. (1913) pp. 114-60 (1 pi. and figs, in text). 



§ Journ. Coll. Sci. Imp. Univ. Tokyo, xxxii. (1913) pp. 1-13 (3 pis.). 



