ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 367 



ship between this species and the two former than has generally been 

 supposed. This resemblance relates not only to their form, but also 

 to their chemical properties. They differ from ordinary proteinaceous 

 crystalloids in being more soluble in water and in the cell-sap of 

 dead cells. Utricularia vulgaris contains also crystals of calcium 

 oxalate of regular octahedral form, but occasionally of a peculiar 

 stellate or rod-like shape. 



Cystoliths in Momordica.*— The occurrence of cystoliths has 

 been at present determined only in the Urticacese and allied orders 

 and in the Acanthacefe and Cucurbitacefe. Dr. 0. PenziCT now finds 

 them in several species of Momordica (Cucurbitaceae), especially M. 

 Charantia and ecMnata. They occur almost exclusively in the leaves ; 

 in some instances also in the bracts. Their location is entirely in the 

 lower layers of the epidermis (hypophyll) ; they are always attached 

 to the radial lateral walls of the cell, presenting in this point a con- 

 trast to those of Ficus. They are never solitary, but always two or 

 more in a corresponding number of adjoining cells. 



In Momordica echinaia the cystoliths are almost always in pairs, 

 and they spring in adjoining cells from opposite points of the same 

 wall. In the earliest stages of the leaf the cells of the hypophyll are 

 all precisely alike. The mother-cells of the cystoliths then become 

 distinguished by their larger size and more strongly refractive cell- 

 contents. When they have attained about four times the size of the 

 ordinary cells, they divide by an anticlinal division-wall, and the two 

 cells thus formed may divide further or not. At a later period the 

 mother-cells of the cystoliths are entirely destitute of chlorophyll 

 and starch, containing only abundant protoplasm. A small protuber- 

 ance of cellulose then appears on each side of the jDartition-wall, 

 which developes into a cylindrical or club shape ; and it is only when 

 nearly fully develoj)ed that the deposition of calcium carbonate takes 

 place in it. The mature cystolith always has, as in the Urticaceae, 

 somewhat the appearance of a bunch of grapes. 



In M. Charantia usually three, four, or five contiguous cells 

 produce cystoliths, one in each, and they then spring all from a 

 common central angle ; but eventually their base widens out, so as 

 almost entirely to fill up the cells. The same process then infects 

 a number of adjoining cells, so that eventually a large and complicated 

 mass is formed, occupying a large number of the cells of the epidermis. 



When the lime is removed by weak acetic acid, a slight skeleton 

 remains, which is coloured dark yellow, passing into brown, by iodine 

 solution or chlor-iodide of zinc. The cellulose reaction can, however, 

 be obtained from it with care, and it probably consists of impure 

 cellulose. 



Sphero-crystals.f — J. Schaarschmidt has detected organic sphero- 

 crystals in four natural orders of flowering plants in which they have 

 not previously been observed, viz. Euphorbiacefe {Eujphorbia), Eutacea) 



* Bot. Centralbl., viii. (1881) pp. 393-400 (3 pis.). 



t Magyar Novenytani Lapok, v. (ISSl) pp. 134-8. See Bot. Centralbl., ix. 

 (1882) p. 46. 



