ALEUR ONE- GR A INS. 
53 
coagulated albumen ; but it may be a yet unknown proteid. With aleurone-grains 
containing crystalloids, after careful solution, a similar membrane remains, but the 
crystalloid itself also leaves behind one of the same kind; this occurs also in the 
solution of globoids in acetic or hydrochloric acid, and reminds one of the similar 
behaviour of true crystals of calcium oxalate. 
The crystalline enclosures of calcium oxalate occur as clusters, distinct crystals, 
and needles, but are not commonly met with. 
The globoids, on the other hand, are never absent 
from aleurone-grains ; when they are accom- 
panied by crystals it is almost always the case 
that the grains of one cell contain only globoids, 
those of another only crystals, as in Silybiim 
marianu7n, and all Umbelliferse that have been 
examined. There occur however exceptions ; 
in the grape-vine a globoid forms itself round 
a crystal or a cluster of crystals. The globoids 
are soluble in all inorganic acids, and in acetiC; 
oxalic, and tartaric acid, but not in dilute 
potash? 
The globoids, like the crystals, may occur 
in an aleurone-grain singly or many together; 
in the latter case they are small, and even too 
minute to be measured, but are then present 
in enormous numbers in one grain, 
Lu- 
FIG. 48.— Cells from the endosperm of Ricinus 
comriiioiis ( X 800). A fresh, in undiluted glycerin, 5 in 
dilute glycerin, C warmed in glycerin, D after treat- 
ment with an alcoholic solution of iodine, the aleu- 
rone-grains are destroyed by sulphuric acid, the 
proteid remaining behind as a net-work. In the 
aleurone-grains the globoid may be recognised, and 
in (/?, C) the crystalloid. 
pinus luteus, L. polyphyllus, Delphinium Requienii, &c. Large globoids surrounding 
crystals occur singly, the largest in the grape-vine. Pfeffer found crystals accom- 
panying crystalloids only in jEihtisa Cynapium. The enclosed substances are usually 
absent from very small aleurone-grains. 
In some seeds there is in each cell one aleurone-fM-ain distino-uished from the 
Others by its size (' Solitar ' of Hartig), both when crystalloids are present and 
when they are absent {Elaeis, Myristica, Viiis, Liipiniis liiteus) ; it may be dis- 
tinguished by its enclosed substances. Thus in Lupinus Intens it contains a tabular 
crystalloid ; the other surrounding grains only small and numerous globoids. In 
Silybum a cluster of crystals lies in one large grain, in the others a number of 
needle-shaped crystals. In other cases the enclosed substances are similar, as is 
the case with the globoids, which are merely larger in the large grain. 
The crystalloids are tolerably widely distributed in aleurone-grains, although 
the greater number of seeds are destitute of them. They are not, however, cha- 
racteristic of natural families, but may be present or absent in members of the 
same family; thus among palms, Sabal Adarisonii is without, Elaeis gui?ieensis has 
crystalloids ; in the same manner all Umbelliferae which have been investigated want 
them except jElhusa Cynapium. In other cases all seeds of the same family appear 
to contain crystalloids, as in the Euphorbiaceae, among which Ricinus supplied the 
first example of fine crystalloids in the aleurone-grains. 
The matrix which surrounds the grains of aleurone in oily seeds is, as has 
been mentioned, always a mixture of oily matter and proteids, but the proportion 
