ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
175 
Bristles of Cirsium liorridum.* — According to Herr A. N. v. 
Arclienegg, the bristles on the upper surface of the leaves of this and 
of other allied species of Cirsium are not trichomes, but are of the nature 
of emergences. They consist of thick- walled lignified and pitted pros- 
enchymatous cells, which are prolonged in a bundle through the paren- 
chyme of the leaf to the end of a vascular bundle, passing into it, and 
being gradually replaced by tracheids. The function of these structures 
is not certain, but they probably act as organs for the absorption or 
storing up of water. 
Stopped Stomates.f — Herr Th. Wulff finds the closing of the 
stomates by a layer of wax, hitherto chiefly known in the Conifer®, to 
be a widely spread phenomenon, having evidently for its object the 
reduction of transpiration. The greatly reduced transpiration of the 
Conifer®, as compared to that of Angiosperms (about 1 : 6), is largely 
due to this. Even when the stomate is not closed on the outside, the 
same result takes place from a partial closing of the communication 
between the pore and the internal air-chamber. The wax-stopper does 
not consist of a homogeneous structure, but of rounded or angular 
granules. It appears to be formed from the guard-cells themselves, or 
from epidermal cells contiguous to them. Even when transpiration is 
greatly hindered, this is not the case with the decomposition of carbon 
dioxide, that gas diffusing readily through a thin layer of wax. In all 
succulent plants examined, the stomates were entirely free from wax. 
The phenomenon is very common in grasses. 
Stomates on the Perianth and Anthers.^— Sig. A. Antony supplies 
additional lists of plants in which stomates are, and are not, found on 
the perianth. In the species of Narcissus examined, stomates were 
found on both perianth-whorls, and on both surfaces ; also on the corona 
and on the connective, but not elsewhere on the stamens. In the snow- 
drop they occur on the inner surface of the outer (upper), and on both 
surfaces of the inner perianth-whorl ; also on the^anthers and filaments ; 
in the wallflower, only on the lower surface of the petals. The spathe 
of Arisarum possesses stomates of a special structure, which necessitates 
their being always open ; while in the spathe of Arum, Calla, Dracun- 
culus, and other Arace®, the stomates are of the normal type. 
Root-tubercles of Leguminosge.§ — M. D. Clos has collected together 
all the facts at present known with respect to the root-tubercles of 
Leguminos®, with an explanation of all the new terms brought into use 
with regard to geotropism and heliotropism, and a statement of the bear- 
ings of recent discoveries on practical agriculture. 
Green Hemi-parasites.|] — Herr H. Heinricher continues his researches 
on this subject, especially with reference to the genera Euphrasia (E. 
salishurgensis , EostJcoviana, and minima ), Alectorolophus, and Odontites. 
The different species of Euphrasia display very different degrees of 
* Oesterr. Bot. Zeitschr., xlviii. (1898) pp. 409-13 (1 pi.). 
t Tom. cit., pp. 201-8, 252-8, 298-307 (1 pi.). 
X Bull. Soc. Bot. Ital., 1898, pp. 170-8. Cf. this Journal, 1898, p. 95. 
§ Journ. Agric. prat, pour le midi de la France, 1898, 18 pp. See Bull. Soc. Bot. 
France, xlv. (1898) p. 321. 
|| Jahrb. f. wiss. Bot., xxxii. (1898) pp. 389-452 (2 pis. and 1 fig.). Cf. this 
Journal, 1898, p. 209. 
