ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 611 



Plants; Classification and special botany of farm crops; Weeds of the 

 farm; Farm Seeds; Fungi, considered chiefly in relation to some 

 common Diseases of Plants ; Bacteria. It is well and clearly written, 

 and is the work of one well qualified to give valuable instruction in 

 the various departments of Agricultural Botany. 



B. CRYPTOGAMIA. 



Cryptogamia Vascularia. 



Parthenogenesis in Marsilea.*— Herr A. Nathansohn states that, in 

 several species of Marsilea, especially 3L Vrummondii, the tendency to 

 parthenogenesis is greatly promoted by an increase of temperature ; 

 while a lowering of the temperature below that of an ordinary dwelling- 

 room, exercises, when other conditions are favourable, but a slightly pre- 

 judicial effect on the process. He regards this as an illustration of the 

 law that the effect of a high temperature on sexual cells is to deprive 

 them of their sexual character and to impart to them vegetative properties. 



Germination of the Spores of the Lycopodiaceae and Ophioglos- 

 saceae.f — M. N. Bernard finds the conditions of germination of the 

 spores of species of Lycopodium, Ophioglossum, and BotrycMum to be 

 very similar to those of the seeds of Orchidese (see p. 607), and to be in 

 some way dependent on the assistance of the endophytic fungus which is 

 constantly found in the cells of the prothallium of these plants. 



Stem of Lycopodium.$ — Mr. L. A. Boodle describes the arrange- 

 ment of leaves in the dimorphic species of Lycopodium, L. volubile and 

 L. scariosum, the resemblance to Selaginella being only apparent. 

 L. salakense differs from other species of Lycopodium in the structure of 

 the stem. The xylem of the stele does not form well-marked bauds ; 

 the tracheids are arranged in small groups aud curved uniseriate rows. 



Regenerating Powers of Cystopteris.§ — Pursuing his investigations 

 on the development of the adventitious buds of C bulbifera and other 

 species of Cystopteris, Herr E. Heinricher has established the following 

 points among others. In C. bulbifera, the buds are always produced on 

 the basal region of the upper side of the fronds : if reversed they are 

 not produced on the side exposed to light. Gravitation has also no effect 

 on the part of the frond where they appear. Iu other species of Cysto- 

 pteris — C montana, fragilis, alpina — adventitious buds are formed on 

 isolated basal portions of the frond, even when the frond has fallen off 

 or is dead; but always on the upper side. The first fronds produced 

 from these adventitious buds are of very simple structure, the lamina 

 being often reduced to little but a mid-rib. 



Algae. 



Assimilation, Metastasis, and Respiration of the Floride9e.||— Herr 

 R. Kolkwitz finds starch to be invariably present in the 6pecies of 



* Ber. Deutsch. Bot. Ges., xviii. (1900) pp. 99-109 (2 figs.). 

 t Rev. Gen. de Bot. (Bonnier), xii. (3900) pp. 115-20. 

 j Ann. ot Bot., xiv. (11)00) pp. 315-7. 



§ Ber. Deutsch. Bot. Ges., xviii. (1900) pp. 109-21 (1 pi.). Cf. this Journal, 189G, 

 p. 654. 



t) Ber. Deutsch. Bot. Ges., xvii. (1899) 1900, Gen.-Vers. Heft, pp. 247-52. 



