ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
501 
Cotyledonary Glands of Rubiaceae.* * * § — Mr. T. Berwick records the 
occurrence of a pair of glands in the axis of the cotyledons in a large 
number of Rubiaceae before germination ; their position and form vary 
according to the species. The process of germination is described in 
the case of a large number of species belong to the order. 
Capitate Hairs with Vibratile Filaments. f — Prof. R. Chodat and 
M. R. Zollikofer record the occurrence of hairs of this description, not 
only in the fluid contained in the cups formed by the coalescence of the 
bases of the leaves in Dipsacus , but also completely exposed to the air 
on plants belonging to the orders Dipsacaceae, Scrophulariacese, and 
Solanacese. Their study is especially easy on the corolla of Antirrhinum 
majus. In the Solanaceae the vibrating filaments form dense cushions 
covering the greater part of the trichome. 
Velamen of Orchids.J — Mr. P. Groom calls attention to the fact 
that the velamen of the roots of orchids does not in all cases perform 
the same function. In some cases it is essentially an absorbent organ ; 
and it is then not confined to epiphytic orchids, but may be present, and 
even assume a higher development, when the root is subterranean ; 
while in other species it is mainly protective, preventing loss of water 
by transpiration, the absorptive function being carried on by the root- 
hairs on the ventral surface of the root. 
Roots of Ranunculaceae.§ — Mr. F. B. Maxwell describes the minute 
peculiarities in the roots of a number of American plants belonging to 
this order. His general conclusion is that, in the Ranunculaceae, it is 
impossible to distinguish the species, and in many cases even the genus, 
by the structure of the root. Environment influences the structure much 
more than specific relations. Plants of different species growing in 
similar conditions present much more resemblance in the structure of 
their roots than those of the same species grown in different conditions. 
The author classifies the species examined under three types as regards 
the changes effected by secondary growth, and under two as regards the 
structure of the meristem of the growing point. 
£. Physiology. 
Cl) Reproduction and Embryology. 
Structure of Hybrids. || — From the examination of a very large 
number of examples, Dr. J. M. Macfarlane arrives at the general result 
that hybrids hold, in their anatomical properties, an intermediate 
position between the two parents. This is displayed in the size, number, 
and position of the trichomes ; in the form and size of the nectaries ; in 
the structure of the cuticle and in the distribution of the stomates ; in 
other anatomical details such as the thickness of the cell- walls ; in the 
form and colour of the chromatophores and the form and size of the 
* Trans. Bot. Soc. Edinburgh, six. pp. 159-65. See Bot. Centralbl., liv. (1893) 
p. 176. 
f Arch. Sci. Phys. et Nat., xxviii. (1892) pp. 494-5. Cf. this Journal, 1892, 
p. 819. t Ann. Bot., vii. (1893) pp. 143-51. 
§ Bot. Gazette, xviii. (1893) pp. 8-16, 41-7, 97-102 (3 pis.). 
(| Trans. R. Soc. Edinburgh, xxxvii. (1892) pp. 203-86 (8 pis.). 
