622 MB. S. LE M. MOOEE'S STUDIES 



and again* on the single similarly surrounded crystals, which he 

 was the first to observe in the fundamental tissue, bast-paren- 

 chyma, petioles, &c, of various Phaseolese. It is scarcely 

 necessary to say that crystals merely attached to the cell-wall 

 are not included in the category of Rosanoff's crystals, the esseu- 

 tial feature of which consists in the relation between them and 

 a support of cellulose developed from the cell's wall. 



It will be observed that up to the present time organs in the 

 full tide of vegetation have been the home of these crystals ; the 

 announcement of their discovery in a resting tissue has now to 

 be made. On freeing sections of the endosperm of Manihot 

 Glaziovii, Mull. Arg., of their oil with ether or alcohol, and 

 washing away, as far as is possible, the closely packed aleurone- 

 grains, the walls of the cells are seen to be everywhere studded 

 with single, twin, and sphere-crystals of small size. Fig. 1 



Fig. 1. 



General view of oil- and aleurone-fre.ed endosperm tissue of Manihot Glaziovii. 



X 450. 



gives a general view of the tissue under a moderate power. The 

 chief forms assumed by the crystals are as follow : — 



(1) Clinorhombic crystals, sessile, or shortly pedicellate upon 

 wall (fig. 1); truncation is sometimes carried further than is here 

 represented. The size varies considerably. 



(2) Sphere-crystals fixed directly to the wall or on short pedi- 

 cells, or occasionally supported on narrow bars running across 

 the lumen of the cell. These spheres differ greatly in size ; they 



* 'Flora,' 1877. 



