ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 621 



Structure and Development. 

 Vegetative. 



Seedling of Torreya Myristica.* — Edith Chick describes the mor- 

 phology and internal structure of the members in seedlings of from 

 16-1 9 months, of this gymnospermous plant. The author lays stress 

 on the retention of certain primitive characters. The lobing and adhe- 

 sion of the hypogeal cotyledons recalls the state of affairs in the two 

 primitive genera Zamia and Ginkgo, and the presence of centripetal 

 wood in the cotyledon is of interest from this point of view ; the trans- 

 fusion tissue has the appearance of being formed from the parenchyma 

 outside the bundle rather than as originating as a direct extension of 

 the centripetal xylem. The method of transition from root-structure 

 to that of the hypocotyl and the petioles of the cotyledons is somewhat 

 exceptional. 



Pathological Plant- Anatomy.f — E. Krister describes in considerable 

 detail the anatomy of diseased or abnormally developed parts of plants. 

 The subject matter is considered under the following headings. I. Re- 

 stitution, where changes in growth, induced by sections and wounds, 

 lead to the new formation of the cut-off parts, or to proliferations of 

 various kinds. II. Hypoplasia, or arrested development due to various 

 inhibiting causes. III. Metaplasie, or progressive changes due to over- 

 stimulations which lead to structural changes in excess of the normal. 

 IV. Hijpertrophie, where the cells attain inordinate dimensions due to 

 excessive growth while young and turgid, e.g. most galls. V. Hyper- 

 plasia, including those abnormalities which arise from an inordinate 

 increase in the average number of cells. In a concluding chapter the 

 author gives a general account of the pathological processes themselves. 



New Secretory Apparatus in Conifers. J — Gr. Chauveaud has dis- 

 covered in members of the Coniferse true laticiferous elements of two 

 kinds : the one formed of a series of more or less elongated elements 

 arranged end to end, the other of single elements of indefinite length 

 but unbranched. Both kinds may occur in the same species, e.g. in the 

 cedar. They show considerable differences in different plants, so that 

 it is necessary to describe them specially in each species. Speaking 

 generally, the wall is thin and not distinguished by any character from 

 the wall of neighbouring parenchymatous cells. The contents are with- 

 out colour or slightly coloured, granular, with suspended drops, forming 

 an emulsion. They are found in different parts of the plants but 

 especially in the pith of the root, while in the stem and leaf they are 

 most abundant under the epidermis. They appear very early, being 

 well developed in the embryo ; they are especially noticeable in young 

 plants. Their number, which is generally very large, is variable, but 

 their distribution in different parts of the plant body is constant for a 



* New Phytologist, ii. (1903) pp. 83-91 (2 pis.). 



t ' Pathologische Pflanzenanatoniie,' bv Dr. Ernst Kiister, 300 pp. of text, 121 

 f.ge., Jena (Fischer), 1903. See also Nature, lxviii. (1903) pp. 244-5. 

 % Comptes Rendus, cxxxvi. (1903) pp. 1093-4. 



Oct. 21st, 1903 2 S 



