244 SUMMARY OF CURBENT RESEARCHES RELATING TO 



organs being enveloped in a vesicle of air. The torsion which a large 

 number of fruits exhibit in falling to the ground is due to the centre of 

 gravity not corresponding to the mechanical centre. 



Development of the Endocarp in the Elder.* — Mr. J. B. Farmer 

 states that if sections of the ovary of Samhucus nigra be made while the 

 bud is still very young, it will be readily seen that the two innermost 

 cell-layers which surround the 2-4 cavities containing the ovules are 

 perfectly distinct both from each other and from those cells which lie 

 immediately outside them ; subsequently, however, a third layer is 

 formed immediately outside these two layers. The cells which compose 

 this third layer are much larger in transverse section than those lying 

 internally to it. The first change which takes place consists in a slight 

 radial extension of the cells, and at the same time the nucleus becomes 

 spindle-shaped. Very soon after flowering, thickening of the cell-walls 

 of each of the three layers commences. Transverse sections taken at 

 a later period show the endocarp, which is very liard and lignified, to be 

 apparently inclosed in a sheath of tangentially flattened cells. 



(4) Structure of Organs. 



Epiderm of the Seeds of Capsicum.t — Herr T. F. Hanausek states 

 that the ordinary description of the seeds of Capsicum is incorrect in one 

 point. Instead of a thick colourless cuticularized outer membrane, he 

 finds, in three species examined, that the outer wall is not cuticularized, 

 but consists of pure cellulose, a true cuticle being wanting or very feebly 

 developed. All the other spots of the membrane of the epidermal cells 

 are very strongly lignified, and the passage from these lignified portions 

 to the lamella of cellulose is a very abrupt one. 



Embryo of Umbelliferse.J -Herr C. Mez describes the specialities 

 in the structure of the embryo in a very large number of genera and 

 species of Umbelliferse. Its position is perfectly uniform throughout 

 the family. Where the form of the seed allows of it, the plane of 

 symmetry of the entire fruit, vertical to the commissure-surface of the 

 mericarp, cuts the plane of the surfaces of contact of the cotyledons at a 

 more or less acute angle. The root-cap of the primary root is always 

 well developed ; the plumule is never formed before germination. The 

 size of the embryo varies very greatly in relation to that of the seed. 

 The two cotyledons are usually of the same length, but in Scandix one 

 is normally longer than the other. 



Winged Stems and Decurrent Leaves. § — Herr K. Eeiche distin- 

 guishes from true wings — on morphological, not on anatomical grounds 

 —the elevated lines and ridges on opposite sides of stems with decussate 

 leaves, which can be compared with the lines of hairs on such stems as 

 those of Veronica Chamsedrys and Stellaria media. Of true wings he 

 distinguishes three kinds, viz. : — (1) where the leaves are continued 

 from their base into two descending wings in immediate contact with 

 the edge of the leaf {Onopordon, Cirs'mm, Gay-duus, Symphytum officinale, 

 &c.) ; (2) where the leaves are distinctly detached from the wings 



* Ann. of Bot., ii. (1888) pp. 389-92 (3 figs.). 



t Ber. Deutsch. Bot. Gesell., vi. (1888) pp. 329-32 (1 pL). 



X Verliandl. Bot. Ver. Piov. Brandenburg, xxix. (1888) pp. 31-6. 



§ Ber. Deutscli. Bot. Gesell., vi. (1888) pp. 323-9. 



