ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 79 



Photolysis in Lemna trisulca.* — Mr. S. Le M. Moore refers to the 

 figures published by Stahl to illustrate the variations in position under- 

 gone by the chlorophyll of Lemna trisulca in consequence of the alterna- 

 tion of day and night (photolysis), but is unable to acquiesce in them as 

 representing the facts according to his impression of them. Stahl's 

 figure shows the chlorophyll of the thin part of the frond ranged upon 

 the side walls during the night, while in the cells of the thick part the 

 inner wall is also studded with chlorophyll, the superficial wall being 

 bare. According to Schimper, however, while all the grains upon the 

 wall abutting upon the epiderm are apostrophized during the night, a 

 few of those ranged during the day upon the inner wall still remain in 

 epistrophe. After giving the details of a number of experiments, the 

 author's conclusions are that, in marginal cells, the eflect of night 

 is to transfer to the side walls only 22 out of the 34 grains in a cell, 

 leaving 12 of them still in epistrophe ; and that in cells from the thick 

 part rather more than 50 per cent, move during the night on to the side- 

 walls, the remainder being fairly equally distributed upon both upper 

 and lower walls. 



Chemistry of Chlorophyll.t — Mr. E. Schunck has continued his 

 contributions to the chemistry of chlorophyll. As one of the products 

 obtained by the action of alkalies on phyllocyanin, the author obtained a 

 substance which he proposes to call phijllotaonin. On spontaneous 

 evaporation of an ethereal solution of phyllotaonin it is obtained in 

 regular flattened crystals or crystalline scales, which by reflected light 

 appear of a fine peacock or steel-blue colour ; the crystals are mostly 

 opaque, but when very thin they are transparent, and then appear brown 

 by transmitted light. The author concludes by describing the various 

 properties of phyllotaonin, and also the compounds it is capable of 

 forming. 



Ch.roinoleucites.| — M. L. Courchet gives details of a great number 

 of observations on the structure and origin of chromoleucites, chiefly in 

 a variety of coloured fruits. 



Among the more important of the general results arrived at, he 

 states that chromoleucites are always formed at the expense of chloro- 

 leucites or leucoleucites. The leucites may also give birth to crystals 

 of colouring matters or to crystalloid substances which originate at the 

 periphery of the stroma or generating layer. The primitive leucites are 

 mostly formed out of starch, but this is usually resorbed before the 

 leucite is mature. The development of the pigment in the leucite may 

 take place in various ways. Blue, violet, red, and rose tints are usually 

 due to coloured fluids, though the blue pigment is sometimes in the form 

 cf crystals or granules. Orange and brick-red tints may be caused 

 either by coloured fluids, or by chromoleucites with either amorphous 

 or crystalline pigment, or by true crystalline or crystalloid formations. 

 The same is true also of yellow tints. 



Chromoleucites are always formed in a proteinaceous substratum or 

 stroma with which are united one or more pigments. Both may be 

 either in an amorphous or in a crystalline condition. The crystals and 

 crystalline formations always consist of pure pigment. Although 



* Joura. of Bot., xxvi. (1888) pp. 353-7. 



t Proc. Roy. Soc, xliv. (1888) pp. 448-54. Cf. this Journal, 1887, p. 606. 



X Ann. Sci. Nat. (Bot.), vii. (1888) pp. 263-374 (6 pis.). 



