CRYSTALLOIDS, 5I 



petals of Fiola tricolor and Orchis, and better developed in the dried fruits of Solarium 

 americanum ; in the latter case they form in the large parenchymatous cells clusters of 

 a deep violet colour; the separate crystalloids are thin rhombic plates, often with 

 truncated angles, &c. According to Nageli the crystalline form is the rhombic prism in 

 a very abbreviated tabular shape ; the six-sided plates are composed of six simple ones. 

 In pure water they remain unchanged ; alcohol extracts the colouring matter, as also do 

 dilute acids ; both leave, after long treatment, a very slight skeleton which is capable of 

 swelling, while the whole crystalloid does not swell ; Nageli states that the crystalloid 

 consists of a very small quantity of albuminous and a large quantity of another substance, 

 with some colouring matter. 



Crystalloids of albuminous substance have also been found in red marine Algae 

 (Florideae) and in one Fungus. Cramer observed the first case of this kind ; in speci- 

 mens of Bornetia secundijlora which had lain a long while in solution of sodium chloride, 

 as well as in specimens in alcohol of Callithamnion caudatum and seminudum^ he found 

 hexagonal plates and prisms with all the properties of crystalloids, and coloured red by 

 the colouring matters of the Algae. They were found in the vegetative cells as well 

 as in the spores. In sodium chloride preparations of Bornetia octohedral crystalloids 

 were found also, apparently belonging to the klino-rhombic system ; they were colour- 

 less. In living plants of the same Alga, Cohn also discovered colourless octohedral 

 crystalloids which absorb the red colouring matter expelled from the pigment-grains. 

 Within and without the cells of Ceramium rubrum preserved in sea-water with glycerin, 

 klino-rhombic prisms formed, coloured red by the exi>elled pigment ; they are clearly, 

 like the hexagonal crystalloids observed by Cramer, produced only after death, while the 



I R colourless octohedra are to be found in the living cells. Finally, in dried specimens of 

 ■other Florideae, Griffithsia barbata, G. neapolitana, Gongroceras pellucidum, and Callithamnion 

 mjeminudum, Klein observed colourless crystalloids of a different form. These bodies 

 ■may all be comprised in the name first given by Cramer, — Rhodospermin. In the 

 fcporangiophores of Pilobolus Klein also found colourless octohedra of tolerably regular 

 Bstructure with the properties of crystalloids. 

 Sect. 8. Aleurone- Grains ^ — The reservoirs for reserve material contained 

 I in ripe seeds, t. e. in the endosperm or the cotyledons of the embryo, always contain 

 considerable quantities of proteids, together with starch or oily matter. If they 

 contain much starch, as in Grasses, Phaseolus, Vicia, the oak, horse-chestnut, 

 Spanish chestnut, &c., the proteid, which only contains very Httle oily matter, 

 occupies the interstices; it then consists of small or even minute granules, as 

 shown in Fig. 46. In oily seeds, on the other hand, in place of the starch-grains 

 are found granular roundish or angular structures (Fig. 47), sometimes not dissimilar 



* These structures were discovered by Hartig (Bot. Zeitg. 1855, p. 881, and described in detail 

 but imperfectly {ibid. 1856, p. 257; [Ann. des Sci. Nat., 1856, vol. VI. p. 325]); further researches 

 were undertaken by Holle (Neues Jahrb. der Pharmacie, vol. X. 1858) and Maschke (Bot. Zeitg. 

 1859). All these observations left undecided the relationship of the grains to the surrounding 

 matrix ; it appeared to be assumed that in oily seeds the matrix consists of oil only. In the first 

 and second editions of this book I opposed this view, and pointed out that the matrix in the cells 

 of oily seeds consists of a mixture of oil and proteids, or rather, of a very oily protoplasm; on 

 the other hand I fell into the error, partly in consequence of the use of diluted ether, of considering 

 the aleurone-grains themselves as a compound of proteids and oil. This error has been refuted 

 by Dr. Pfeffer's recent researches, commenced in the Wlirzburg laboratory, where I had the oppor- 

 tunity of seeing numerous preparations which were decisive as to the principal question. Dr. Pfeffer 

 had the kindness to communicate to me a detailed account of his labours ; what I have said above 

 follows his views tolerably closely. See Pfeffer, in Pringsheim's Jahrb. fur wissens. Bot. vol. VIII. 

 p. 429. 



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