ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
647 
honey-bee. In Lilium candidum .self-pollination is almost impossible ; 
while in L. testaceum and chalcedonicum it may readily occur, though 
probably the ordinary mode of pollination is by visiting insects. 
Mr. J. H. Lovell * * * § describes the structure of the flower and enume- 
rates the visiting insects observed in Gaultheria procumbens (proter- 
androus, Apidse) ; Glielone glabra (not self-pollinated, species of Bomnbus ) ; 
Impatiens biflora (Apidse) ; Cornus canadensis , stolonifera, and alter ni folia 
(self-pollination generally prevented, a great variety of visitors) ; Aralia 
racemosa (strongly proterandrous, a great variety of visitors, as many 
as 80 species). 
Hybridism.-j' — Dr. M. Abbado reviews the state of our knowledge 
at present, and the literature on the subject of the production of hybrids 
in the vegetable kingdom, especially with reference to the morphological 
characters of the hybrids as compared to those of the two parents. He 
regards hybridism as an effectual origin of new species. A very copious 
bibliography is appended. 
Knuth’s Handbook to the Biology of Flowers.}; — This most im- 
portant work completes the survey of this branch of vegetable physio- 
logy from the publication of Muller’s c Befruchtung der Blumen ’ down 
to the present date (April 1898); every important observation made 
during the past quarter of a century being recorded. The first volumo 
comprises a review of the literature of the subject to the present time, 
and treats of the various modes of pollination and of distribution of 
the sexual organs, cleistogamy, parthenogenesis, the different classes of 
insects and of other animals that contribute to the carriage of pollen, 
the part played by the conspicuousness of flowers, their scent, Ac. In 
the first part of the second volume are contained the records of observa- 
tions on particular species of plants in Europe and the Arctic region, 
from Ranunculacese to Compositae ; the adaptations of the flow r ers them- 
selves and of the visiting insects being in each case described. The 
second part of the second volume will contain similar details from the 
Lobeliacete to the Coniferae ; and a third volume will be devoted to 
observations on extra-European plants. 
(2) Nutrition and Growth (including- Germination, and Movements 
of Fluids). 
Influence of Mineral Salts on the Form and Structure of Plants. § 
— From a series of experiments on a great variety of plants, M. C. 
Dassonville states, as a general law, that the mineral solutions most 
favourable to the growth of plants are those which incite the greatest 
amount of differentiation. There are special differentiations which are 
localised in particular tissues. For example, the pericyclic fibres be- 
come more abundant, the fibro vascular bundles increase in importance, 
* Bull. Torrey Bot. Club, xxv. (1898) pp. 382-90. 
f Nuov. Gioru. Bot. Ital., v. (1898) pp. 76-105, 265-303. 
X Knuth, P., ‘Handbuch d. Bliitenbiologie,’ BJ. i. Einleitung u. Litteratur, 
400 pp., 81 rigs., and 1 portrait. Bd. ii. Th. i. Ranunculaceae — Compositae, 697 pp., 
210 tigs., and 1 portrait. Leipzig, 1898. 
§ Rev. Gen. de Bot. (Bonuier), x. (189S) pp. 14-25, 59-68, 102-24, 161-70, 193-9, 
238-60, 289-304, 335-44 (10 pis. and 4 figs.). Comptes Rendus, csxvi. (1898) 
pp. 856-8, Cf. this Journal, 1896, p. 643. 
