ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 51 



yellow amorphous mass, soluble iu all proportions in water and alcohol, 

 insoluble iu ether, chloroform, benziu, and carbon sulphide, slightly 

 hygroscopic, and melting at 190°, Injected into frogs and pigeons, it 

 acts as a heart-poison. Ervsimin belongs to the class of digitalins, and 

 is analogous to the glucoside of Oheiranthus. 



Exosmose of Diastases.* — As the result of experiments on various 

 seedlings, J. Laurent states that during germination a portion of the 

 amylase formed in the seeds may pass out by exosmose ; but this process 

 ceases on germination; the young roots do not possess this property. 

 In the case of the sugar-cane small quantities of sucrase are also thrown 

 out. The object appears to be to facilitate the digestion of starch in the 

 cells which envelope the meristem. 



Seminase in Seeds, f — Pursuing their investigation of seeds with 

 horny endosperm, E. Bourquelot and H. Herissey find that (in Medicago 

 sativa and Indigo/era tinctoria), wheu in a dormant condition, there is 

 always a small proportion of the soluble ferment seminase, which is 

 capable of hydrolysing the endosperm and transforming it into sugars 

 capable of assimilation, viz. galactose aud mannose. 



Presence of an Inverting Sugar in Grapes. X — V. Martinaud has 

 established the presence, in the juice of all kinds of grape, of a sucrase 

 (inverting sugar, invertin) in sufficient quantity to invert the whole 

 of the saccharose present, without the assistance of the organic acids. 

 It is not present in vines attacked by bacterial diseases, and disappears 

 entirely in wines which have been strongly oxidised. 



Simultaneous occurrence of Two Sugars. § — E. Bourquelot and 

 H. Herissey record the simultaneous presence, in the root of the yellow 

 gentian, of two carbohydrates of the nature of sugars, viz. saccharose 



and gentianose. 



(3) Structtire of Tissues. 



Order of Formation of the Elements of the Central Cylinder in 

 the Root and Stem.|| — From a study of the central cylinder in flower- 

 ing plants, Prof. G. Bonnier concludes that it presents the same general 

 plan of structure in the stem and in the root ; the constitution and the 

 order of development of the tissues are the same in both cases. The 

 only difference is in the position of the xylem-poles, which, in the root, 

 are turned backwards towards the periphery of the central cylinder. 

 It follows that the first vessel formed near a xylem-pole of the root 

 originates not far from the primary cortex, i.e. in the neighbourhood of 

 the tissue which regulates the current of water which passes from the 

 root-hairs to the xylem- vessels. The author regards this difference as 

 depending on a correlation between the arrangement of the vascular 

 tissue and the absorption of water. 



Anatomy of Monopodial 0rchids.1T — L. Hering describes in great 

 detail the structure, especially of the fertile stem, in a large number of 



* Comptes Rendus, cxxxi. (1900) pp. 848-51. 

 t Tom. cit., pp. 903-5. Cf. thia Journal, 1900, p. 479. 

 t Tom. cit., pp. 808-10. § Tom. cit., pp. 750-52. 



|| Tom. cit., pp. 781-9 (6 figs.). 



1 Bot. Centralbl., lxxxiv. (1900) pp. 1-11, 35-45, 73-81, 113-22. 145-52, 177-84 

 (3 pis.). 



E 2 



