ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 569 



generally sharply distinguished into palisade and spongy layers, the 

 former often one layer thick. Calcium oxalate was generally present ; 

 hesperidin was frequently observed in the epidermis. 



The author does not consider that a sufficient number of genera was 

 investigated in the subdivisions of the order to draw definite con- 

 clusions as to the systematic value of the anatomical characters. He, 

 however, indicates the following points of interest : — The almost con- 

 stant occurrence of mucilage in the epidermis of the Diosmeae. In 

 other groups it was less constant or not observed in the genera in- 

 vestigated. The structure of the palisade parenchyma showed some 

 agreement in individual groups. In the Toddalieaa it was always one- 

 layered, as also in the Boronie®, except in Boronia (two-layered), in the 

 Aurantiese always several-layered, and of almost cubical cells. In other 

 tribes the number of layers was variable. 



Dischidia with Double Pitchers. * — H. H. W. Pearson describes 

 the occurrence of double pitchers in four species of Dischidia, from the 

 Philippines and Borneo. The second or inner pitcher is formed by 

 the involution of the leaf-apex, which, in the simple pitcher of D. 

 Bafflesianum, hangs free in the pitcher. The outer pitcher contains solid 

 matter and roots ; in two cases ants were found. The opening into the 

 outer pitcher being only 2 mm. in diameter, is not large enough to allow 

 of the washing in of solid matters by rain ; and the author suggests, 

 therefore, that the material is carried in by the ants, indicating a degree 

 of myrmecophily which is an advance upon that shown by D. Bafflesianum. 

 There were no roots in the inner pitcher. In one species, D. pectinoides, 

 a large number of small, irregular-shaped sweet masses were found in 

 the inner pitcher ; these arise from gummosis of the tissue above the 

 opening of the inner pitcher. On the surface of the inner wall of the 

 outer pitcher a fungus mycelium was present, the hyphae of which 

 abstrict gemmaa, which perhaps serve as food for the ants. 



Precursors of Sieve-tubes in Gymnosperms.f — G. Chauveaud de- 

 scribes elements which precede the sieve-tubes in order of development, 

 and are in their position and character intermediate between the cells 

 of the pericycle and the first-formed sieve-tubes. The first are tubular 

 in form, with a thin wall, and no appreciable modification. These are 

 followed, by elements, tubular like the first, but also provided at certain 

 points in their walls with a little sieve-area. Other elements show a 

 still higher degree of differentiation. The limit between pericycle and 

 bast is not therefore abrupt, as in the angiosperms ; we pass from the 

 cells of the pericycle to the first sieve-tubes through a series of forms 

 showing increasing differentiation. These intermediate forms, which 

 are transitory, give a primitive character to the bast which corresponds 

 with the ancient origin of the group. These precursory elements are 

 best seen in the seedling before the cotyledons have completely spread. 

 Their differentiation can be followed from the radicle into the cotyledons, 

 and they can be found also at the origin of each young rootlet. 



Botanical Origin of Kinkeliba. % — E. Perrot and G. Lefevre have 

 investigated the histology and external morphology of this tropical 



* Journ. Soe. (Bot.) Linn., xxxr. (1902) pp. 375-89 (1 pi.). 

 t Comptes Rendus, c.:xxiv. (1902) pp. 1605-0. % 'Join. 



cit., pp. 1154-6. 



