ZOOLOGY AND BOTANY* * * § MICROSCOPY* ETC, 
57 
what he believes to he the ideal of nature, but he who, availing himself 
of all the information which the histology, embryology, and ecology of 
the day can furnish, defines his species within broad rather than narrow 
limits, in clear and sharply cut words which can be readily compre- 
hended, and do not force one to resort to original and perhaps single 
specimens to learn what the author of the species really meant.” 
Myrmecophilous Plants.* — Herr W. Taliew adds the following to 
the list of known myrmecophilous plants : — Pseonia tenuifolia , Vicia 
Faba, V. septum , V. pannonica , V. grandiflora var. Biebersteinii, V. trun- 
catula , V. sativa, Centaurea ruthenica , C. montana var. axillaris , Fraxinus 
excelsior , Lamium album , Iris Gueldenstaedtiana. The author disputes 
the benefit of myrmecophily to the plant infested by the ants, its flowers 
being often destroyed by them. 
Ant-gardens, j — M. M. Raciborski describes a species of Ampelidese, 
Leea hirsuta, a native of Java, in which il food-bodies ” are produced, 
which are greedily devoured by ants, and are difficult to detect, from the 
eagerness with which the ants consume them. They consist of small 
round bodies, borne on the young parts of the stem or on the young 
leaves, most abundantly on the leaf-stalks. The cells are filled with 
starch-grains and large drops of oil. 
Value of Hybrids in Plant-breeding4 — Mr. W. T. Swingle and 
Mr. H. J. Webber give a detailed account of the production of hybrids 
and of their value in plant-breeding. They describe the methods used 
in producing hybrids, their characters in relation to those of the parent 
plants, the preponderating influence of one parent in determining the 
characters, the prepotency of pollen from one plant over that from 
another, the increased vigour of hybrids and cross-bred plants, the direct 
action of foreign pollen on parts of the mother-plant, the production of 
graft-hybrids, and other points of special value to the plant-grower. 
Temperature of Plants.§ — Herr F. Schleichert has made some inter- 
esting observations on the temperature of trunks and leaves. In Pavia 
rubra , the temperature in the interior of the trunk, at a depth of 12 cm. 
below the surface, was found to be in the first place dependent on that 
of the surrounding air, attaining its maximum and minimum some hours 
later than that of the atmosphere, viz. the former about midnight, the 
latter between noon and 3 p.m. It is also, however, influenced to a less 
extent by the temperature of the soil and of the ascending current of 
water, and by the degree to which the leaves are exposed to direct sun- 
light. The temperature of the leaves was found to be in some cases 
slightly (0*7° C.) below that of the surrounding air, owing to transpira- 
tion ; but in other cases (aloe, cactus) much higher, when exposed to 
bright sunshine (28 *5° as compared with 20°). This is not due to a 
development of heat in the leaf, but to the absorption of heat through 
the thick mass of the leaf (or stem). 
* Arb. Naturf. Gesell. k. Uuiv. Charkow, Beilage, 1898, pp. 41-4. See Bot. 
Centralbl., 1898, Beih., p. 93. f Flora, lxxxv. (1898) pp. 257-61 (1 fig.). 
X Year-book Department of Agriculture U.S., 1897, pp. 381-420 (2 pis., 13 figs.). 
§ Naturw. "Wochenschr., xiii. (1898) pp. 469-72. 
