BOTANY. 1053 



use of "evergreen" so as to differentiate between those which are simultaneously 

 deciduous and those which have leaves persisting for more than one year. 



A number of species of plants were examined and it was found that the evergreen 

 trees and shrubs in the vicinity of Naples differ greatly in the longevity of their 

 leaves, some of the species having leaves that live only about 15 months, while others 

 live for 2i years. All of the leaves studied reach their maximum area development 

 considerably before they attain their full thickness. The leaves of 6 out of the 8 

 species studied transpire more for equal areas when 15 to 18 months old than they 

 do when they have just reached their maximum area, which takes place when they 

 are about 3 or 4 months old. Transpiration for equal weights of leaves is generally 

 more active for leaves of 15 or more months than for those 3 months old or a little 

 older. Epidermal transpiration bears a much smaller ratio to total transpiration in 

 leaves of 3 months than those of 15 months. 



Artificial parasitism. (I. J. Peirce i Bot. Gaz., 38 {1904). No. 8, pp. 214-217).— 

 A preliminary account is ^iven of experiments which indicate a sort of artificial 

 parasitism of peas. The author germinated a number of seeds of peas, and when 

 the radicles hail attained a length of 1-2 cm. he inserted them in plants of Viciafaba. 

 About 15 cm. above the soil holes were cut with a sharp scalpel in the bean stalks 

 and the radicle of the pea inserted, being pushed into the stem as far as the cotyle- 

 dons. Afterwards a plaster of Paris mold was formed about the peas for their 

 support. 



These pea-bean plants were grown in pots in a cold frame, and at the same time 

 from the same lot of seed others were sown in soils under ordinary conditions. The 

 peas flourished, blossomed, and produced seed which were but slightly smaller than 

 those produced by the soil-grown plants. The plants themselves, however, were 

 considerably reduced in size and weight by the semiparasitism. 



Later the seeds produced by the bean-peas were germinated and again inserted in 

 bean plants as described above. These grew, making a second generation of arti- 

 ficial parasites the roots of which had never been in contact with the soil. The peas 

 grew into vigorous, well-proportioned, healthy plants, although somewhat smaller 

 than those of the preceding season. There was no tissue union between the host 

 plant and the parasite. The roots grew downward through internodes and nodi"-, 

 but never reached the level of the soil, much less the soil itself. 



The experiment was terminated by an accident, but it seems to throw some light 

 on the question of the beginning of parasitism. 



Hyphoids and bacteroids, P. Yrn.LE.Mix (Compt. fiend. Acad. Sri. [Paris'], 140 

 (190.5), No. 1, }>i>- •'-', 53). — The author describes a form of hyphal filaments which 

 is found during winter on the roots of various legumes and which has been pre- 

 viously described as belonging to the fungus Cladochytrium luberculorum. A more 

 recent study of the material shows that it belongs to the genus Pythium. The 

 hyphse become massed together, surrounded -with a mucilaginous capsule, and in 

 many respects are analogous to the bacteroids observed in the root tubercles of 

 leguminous plants. 



Conditions of accumulation and reduction of nitrates in plants, X. Xedoe- 

 vochayev (Izc. }{<>«<■<,)■. Selsk. Khoz. Inst. [Ann. Inst. Agron. Moscou], 10 (1904), No. 

 1, pp. 251-841 ). — This elaborate treatise is divided into 8 chapters: 



(1) The distribution of nitric acid in the plant kingdom is discussed, and a long 

 list, with authorities, is given of the plants in which nitric acid has been definitely 

 ascertained. (2) The method used by the author for determining the nitric acid 

 was essentially that of Sehloesing as modified by Tiemann. The nitric acid was 

 determined in week-old plants raised in water cultures. (3) The origin of the 

 nitrates in the plants is discussed. A critical survey of the literature establishes the 

 fact that nitrates accumulate in plants only when the soil or the medium in which 

 they grow contains nitrates. By accurate experiments with Helianthus annum, Zea 



