BOTANY. 841 



l)lanti=. The cereals and grasses seem to possess this -power in a limited way and 

 k'guniinous plants to a considerably increased degree. Cruciferous plants and l)uck- 

 wheat are able to dissolve the mineral phosi>hates (juite readily, as are potatoes and 

 some other crops. A knowledge of the ability of crops to render soluble the mineral 

 phosphates in fertilizers is an advantage in determining what fertilizers to use. 



The physiolog-ical role of nicotin in the tobacco plant, G. Albo {Conlrih. 

 niol. Vnj. Roy. Isf. Bot. Pnh'rnio, S {190;.'), No. 1, jijt. 69-91). — In the author's inves- 

 tigations on the role of nicotin in the tobacco plant he found that this substance 

 does not occur in the seed, but a substance similar to solanin is abundant in the i^eed 

 and during the process of germination aids materially in tlie development of the 

 plant. When the young seedlings have become well established and assimilation 

 lias begun, nii'otin appears in certain cells of the hyj^ocotyl and in the leaves, and 

 later the alkaloid is found distributed throughout all the tissues. The total amount 

 of nicotin in a plant varies with the conditions under which the plant is grown. If 

 of 2 plants cultivated side by side the top be cut from one and the other allowed to 

 flower and mature its seed, the greatest amount of nicotin will be found in the plant 

 which has been topped, in some cases amounting to 3 times as much as that found 

 in the plant which is allowed to mature. The nicotin which is formed by the plant 

 is carried to the seed and there transformed into solanin or some similar substance. 

 The experiments conducted with plants in darkness and in atmospheres dejtrived of 

 carbon dioxid seem to indicate that nicotin has its origin in the leaves and that it is 

 one of the products dejiendent upon the assimilation by the plant. Nicotin, it is 

 claimed as the result of the author's investigation, is either directly or indirectly 

 concerned in the nutrition of the tobacco plant. 



The biology of asexual reproduction of flowering plants, A. Terracciaxo 

 {Contrlh. niol. Veg. Hoy. Id. Bot. Palermo, 3 {1903), No. 1, p}). 1-66', jjIs. 6) .—The 

 asexual reproduction of phanerogams is held by the author to be a device on the 

 part of many plants to provide against the possibility of a failure of reproduction 

 tlirough seed. Such plants are less plastic than those grown from seed, a fact often 

 taken advantage of in grafting, budding, etc. The different forms and conditions 

 vnider which asexual reproduction may take place are enumerated, and the various 

 biological phenomena observed by the author are described. The author's investi- 

 gations were made on a number of species of plants, many of which were cacti, 

 euphorbias, etc. The anatomical structure and biological relationships between 

 parent plant and offshoot are to be treated in a subsequent paper. 



Root tubercles of Datisca cannabina, A. Trotter {Bui. Soc. Bot. Ital., 1902, 

 No. 2-S,pp. 50-52; ahs. in Bot. Cenihl., 90 {1902), No. 8, p. 196) .—A preliminary note is 

 given descriV)ing root tubercles whic-h have recently been studied by the author, and 

 he shows that they are formed by masses of fundamental tissue which contains 

 hypertrophieil nuclei l)ut little or no starch, and the principal content of the cells is 

 made \^\^ of bacteria which greatly resemble those known as Bacilltis radicicohi. 



Green hemiparasites, E. Heinrichek (/a/ir6. Wis.'i. Bot. \_Pnngsh.eim'\, 37 {1902), 

 No. 2, pp. 264-337, pis. 2; ahs. in Jour. Roy. Micros. Soc. ^London], 1902, No. 4, PP- 451, 

 452). — Descriptions are given of culture experiments made with Euphrasia with a 

 view of ascertaining whether the chemical properties of the host plant were preju- 

 dicial to the growth of the parasite. It was found that T)oth Euphorbia and Oxalis 

 serve equally well as host plants in spite of the widely different chemical qualities of 

 their cell saj). The claim that monocotyledons serve exclusively as host plants for 

 these semiparasites is shown to be wrong, the author cultivating 3 species on widely 

 different host plants, obtaining perfect development in every case. It was also shown 

 that a single individual may attach itself at the same time to the roots of at least 2 

 different hosts. Investigations were also made on the relation of nutrition to the 

 general habit of the plants. Studies were undertaken to decide how far parasitism 

 was capable of being replaced by a saprophytic habit, and it is shown that while a 



