ZOOLOGY AND BOTA.NY, MICROSCOPY, ETC. 513 



Vegetative Activity in the Carboniferous Epoch.* — B. Renault 

 cites various cases in proof of the statement that there was formerly a 

 much greater activity in formation of cellular tissue than at present. 

 One instance is found in the organisation of the pollen-grains ; those 

 of Stephanospermum, Corclaites, and other Gymnosperms contain a pro- 

 thallium of from 8 to 12 cells, while in present day Gymnosperms no 

 more than 3 or 4 are found. This activity was favoured by a remark- 

 able development of the nourishing vascular strands. For instance, the 

 author has shown that the embryo-sac of Stephanospermum was sur- 

 rounded by bundles of tracheids, while the filament of the stamens in 

 Corclaites was traversed by an important vascular bundle which formed 

 a branch for each anther. 



Notes on Composite .j — R. Wagner has studied the morphology of 

 the inflorescence in a number of genera of Compositse. 



Seeds of Inga.f — A. Borzi describes the biology of the seed dis- 

 tribution and germination in Inga Fevillei and other species of this 

 genus of Leguminosas. 



Laticiferous Tissue in Flowers of Convolvulaces3.§ — P. Grelot 

 finds three types of this tissue : — (1) Strings of cells placed end to end 

 with suberised membrane and absorbed transverse walls ; branchings 

 occur. These are very regularly distributed, accompanying the nerves in 

 calyx, corolla, and stamen, and localised at the periphery in the ovary 

 and style. (2) Isolated cells, with suberised membrane coexisting with 

 (1) (Convolvulus Cneorum), or occurring alone with no precise localisa- 

 tion. (3) Cells fusing to form branched or simple cell-groups ; mem- 

 brane of cellulose. These are the rarest and occur in Fallcia and 

 Dichondra. They are generally subepidermal and have a scattered 

 distribution in the calyx, but are localised at the base of the corolla and 

 pistil. The author finds that the laticiferous tissue does not afford 

 constant characters for distinguishing species of a genus. 



Physiology. 

 Nutrition and Growth. 



Synthesis of Proteids by Plants. || — Em. Laurent and Em. Marchal 

 divide their paper into two parts. In the first, which is historical, the 

 sources of plant nitrogen, their assimilation by the plant, and the pro- 

 ducts of assimilation are considered from the point of view of previous 

 work. In ,the second part the experiments made by the authors are 

 described. Seedlings of mustard and cress, shoots of onion, asparagus, 

 white mustard, leaves of Nicotiana and- Syr inga were among the subjects 

 of investigation. The following conclusions are tabulated. Free 

 nitrogen is assimilated by lower organisms : — Clostridium Pasteurianum, 

 different species of Bacteria and Nostoc (?), and EhisoUum when culti- 



* Comptes Eendus, cxxxvi. (1903) pp. 401-3 (8 figs.). 



t Verhandl. k. k. Zool. Bot. Gesell. Wien, liii. (1903) pp. 21-G5 (6 figs, in text). 

 X Atti Reale Accad. d. Lincei, Rendi. CI. Sci. fis., &c, xii. (1903) pp. 131-40. 

 § ' Recberches sur les laticiferes de la fleur des Convolvulacees,' Nancy, 1902, 

 23 pp. (17 figs.). See also Bot. Centralbl., xcii. (1903) p. 83. 

 || Bull. CI. Sci. Acad. Roy. Belg., 1903, pp. 55-114. 



