256 SUMMARY OF CUBEENT RESEARCHES RELATING TO 



cell, but their substance is probably used up in the processes which sub- 

 sequently go on in the cell, for the absorption of the crystals takes place 

 even in unfertilized blossoms. The absorption may be effected in various 

 ways. 



The formation of crystalloids appears to have a certain relationship to 

 the production of flowers and fruit. In Latlirsea they are found only in 

 the flower-bearing stems ; in Pingnicida they remain until the appearance 

 of the blossoms. In contrast to other albuminous substances, crystalloids in 

 the nucleus are either confined to the superficial cells, or are most abundant 

 in them. In TJrlica and Campanula they are found only in the trichomes. 



Chromoleucites.*-— The chromoleucites of flowers and fruits are stated 

 by M. L. Courchet to be foi-med either from a stroma of proteinaceous 

 character, which is generally colourless, or from pigment-granules of a 

 certain degree of fluidity and of variable size scattered more or less 

 regularly in the stroma. He enumerates five distinct types of pigment, 

 viz. : (1) True crystals formed from the pigment alone without any 

 admixture of protoplasm (root of carrot, fruit of tomato, melon, and 

 cucumber). (2) Eounded, or of an irregular contour, with a homogeneous 

 appearance, owing to the minuteness of the pigment-grains (berry of 

 asparagus. (3) Sj^indle -shaped, or of the form of a plate with many points 

 (fruit of honeysuckle). (4) The coloration is due to a coloured sap 

 (ovary of Salpiijlossis). (5) The colour is due neither to chromoleucites 

 nor to a coloured sap, but to an orange-yellow coloration of the walls of 

 the external cells (fruit of several species of Solanum). 



Colouring Matter of Aceras anthropophora.t — Sig. P. Severino has 

 studied the nature of the colouring matter in the flowers of the variety 

 purpurea of the man-orchis. He finds it to be due to a solid granular 

 substance which is probably a modification of chlorophyll. 



Nageli's Starch-cellulose.J — Herr A. Meyer disputes the theory of 

 the structure of starch-grains first put forward by Niigeli, and since 

 generally adopted, that they consist of an intimate admixture of two 

 distinct substances, true starch (granulose), and cellulose (farinose). The 

 action on starch-graius of either saliva or concentrated sulphuric acid 

 entirely removes the granulose, leaving behind a skeleton composed of a 

 substance which has been termed amylodextrin. 



According to Meyer, amylodextrin always results when starch-grains 

 are treated with dilute acids, diastase, pepsin, or saliva, this being the 

 first result of hydration at a low temjjerature, afterwards passing over into 

 dextrin and soluble sugar, the skeleton also then entirely disappearing. 

 It is diflicult to obtain amylodextrin entirely free from dextrin and sugar ; 

 and this would be impossible were it not that it has a tendency to aggregate 

 into sphero-crystals very similar to those of inulin ; these sphero-crystals 

 are occasionally disc-shaped, more often spherical, often laminated, and 

 closely resemble centric starch-grains, even in their appearance under 

 polarized light. Micro-chemical examination shows almost conclusively 

 that the skeletons obtained by the action of acids and of saliva on starch- 

 grains and amylodextrin, are identical substances. Amylodextrin and 

 " starch-cellulose " are, therefore, not present in the intact starch-grain, but 

 are products of the action upon it of hydrating agents, and there is only 

 one substance present in normal starch-grains, which the author proposes 

 to call " starch-substance." 



* Bull. Soc. Bot. France, viii. (188G) pp. 178-81. 

 t Niiov. Giorii. Bot. Ital., xviii. (188G) pp. 315-9. 

 X Bot. Ztg., xliv.,(18Sb) pp. G07-703, 713-9. 



