ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 321 



Influence of Pollination on the Development of the Pericarp.* — 

 E. Tschermak gives an account of experiments on the wallflower. He 

 finds that by use of pollen from another individual of the same form or 

 the same variety, the pods were almost twice as long and proportionately 

 broader than when pollination was effected by means of the same flower 

 or another flower of the same plant. The large pods also contained 

 more than a third more seeds, and the seeds were 70 p.c. heavier than in 

 the smaller. The stigmas also behaved somewhat differently in the two 

 cases. The author explains the stronger development of the fruit partly 

 by the increased seed-production, but considers it duo in part to the 

 direct vegetative influence of pollination. 



The same author f describes some experiments with pea hybrids on 

 the correlation between vegetativo and sexual characters. He crossed 

 some red-flowered kinds of Pisum arvense having wrinkled cotyledons 

 with white-flowered smooth-seeded kinds of P. sativum, but never found 

 any alteration of the cotyledon form in the seeds of the mother-plant. 

 The hybrids were all red-flowered with wrinkled seeds. The second 

 generation of hybrids produced one white-flowered to three red-flowered 

 individuals ; the latter bore exclusively wrinkled, the former only 

 smooth seeds. This behaviour is directly opposed to rosults previously 

 obtained in crossing wrinkled and smooth-seeded forms of P. sativum, 

 where the smooth-seed form dominated the wrinkled. 



Microscopic Characters of the Fruit-Envelopes in the Acorn.J— 

 With a view to their recognition as an adulterant in acorn coffee, W. 

 Mitlacher describes the minute structure of the cupule and pericarp of 

 Quercus sessiliflora. The former consists mainly of parenchyma bearing 

 numerous nests of stone-cells of very different form, and containing some- 

 times crystals ; the outer epidermis is of polygonal cells, and bears very 

 numerous one-celled hairs. The pericarp has below the smooth outer 

 epidermis, in succession, a layer of crystal-bearing cells, a layer con- 

 sisting of several rows of radially elongated stone-cells, a partly col- 

 lapsed median layer with solitary crystal sacs, an internal layer of soft 

 parenchyma, and, in the interior, an epidermis bearing numerous one- 

 celled thin-walled hairs. 



Development of the Seed in SapindaceseJ — P. Guerin has studied 

 the development of the seed-coats and endosperm in species representing 

 a number of genera of this family. The ovule has always two integu- 

 ments, the outer of which generally forms the bulk of the seed-coat, as 

 in Cardiospermum, JEsculus, and others. In Staphylea the inner integu- 

 ment plays a somewhat more important part, while in Acer it is equal 

 in importance to the outer. Endosperm is copious in Staphylea and 

 Melianfhus, but in Koelreuteria and Xanthoceras is reduced to a single 

 layer (Guignard's " proteid layer "). In Cardiospermum it occurs only 

 as isolated cells, especially near the radicle, as Guiguard has previously 

 shown to be the case in Geraniacese. In JEsculus and Acer it is quite 

 absent, the nuclei never becoming organised into a tissue within the 

 embryo-sac. 



* Bot. Zeit., xx. (1902) pp. 7-16 (1 pi.). + Tom. cit., pp. 16-21. 



X Zeitschr. allgem. osterr. Apothek.-Verein, 1901, Nos. 1 and 2 ; and in Verhandl. 

 zoolog.-botan. Ges. Wien, hi. (1902) pp. 136-7. 

 § Journ. de Botan., 1901, pp. 326-62 (24 figs.). 



