CRYSTALLOIDS, 
51 
petals of Fiola tricolor and Orchis, and better developed in the dried fruits of Solanum 
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 Nägeli 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 ; Nägeli 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 
(Floridese) and in one Fungus. Cramer observed the first case of this kind ; in speci- 
mens of Bornetia secundiflora 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 Ceramimn rubrum preserved in sea-water with glycerin, 
klino-rhombic prisms formed, coloured red by the expelled pigment ; they are clearly, 
like the hexagonal crystalloids observed by Cramer, produced only after death, while the 
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 
seminudum, Klein observed colourless crystalloids of a dilferent form. These bodies 
may all be comprised in the name first given by Cramer, — Rhodospermin. In the 
sporangiophores of Pilobolus Klein also found colourless octohedra of tolerably regular 
structure with the properties of crystalloids. 
Sect. 8. Aleurone- Grains ^ — The reservoirs for reserve material contained 
in ripe seeds, i. 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 little 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 {ihid. 1856, p. 257; [Ann. des Sei. 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 Würzburg 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. für wissens. Bot. vol. VIH. 
p. 429. 
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