494 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Anatomy of the Malvaceae.* * * § — Herr G. Kuntze finds the following 
characters common to all species of Malvaceae examined : — Small, usually 
brown capitate hairs ; strong bast-bundles in the cortex ; and especially 
mucilage in the cortex and pith, as well as in the epiderm of the upper 
surface of the leaves. The leaves are bilateral, and have palisade-cells 
on their upper surface only ; crystals, both solitary and in clusters, are 
common, but never raphides. The hairs are very commonly stellate, 
and occasionally chambered. Mucilage occurs in all organs, and results 
from the disintegration of the cell-walls. The Bombaceae differ in so 
many respects from the typical Malvaceae that they ought, perhaps, to 
be regarded as a distinct order. They rarely possess stellate or tufted 
hairs; and the wood is in general less lignified, and contains larger 
vessels; mucilage-passages occur almost invariably on the under side 
of the larger veins. The author was unable to lay down any anatomical 
character for the separation of the genera. 
£. Physiology. 
(1) Reproduction and Germination. 
Results of continual Non-sexual Propagation, f — Prof. M. Moebius 
discusses this subject in detail as regards flowering plants, and decides 
against the Darwinian hypothesis that continual propagation by non- 
sexual method must result in deterioration and ultimate extinction. He 
agrees with Schleiden in dissenting from the popular theory that the 
offspring of such modes of propagation must be regarded as constituting 
but a single individual. In support of these views he refers to the 
length of time — extending in some cases to thousands of years — during 
which some plants have been continuously propagated by non-sexual 
methods without apparent deterioration or increased liability to disease 
— e. g. Elodea canadensis , the fig, the date-palm, the banana, the yam, the 
batatas, the olive, and many others. On the other hand, the weeping- 
willow and the Lombardy poplar do appear to have been threatened with 
extinction, owing to their abnormal liability to disease. But degenera- 
tion as the result of age cannot be affirmed as a general law in such cases. 
Cross-fertilization and Self-fertilization4 — Mr. E. G. Hill describes 
in detail the mode of pollination in three American plants ; — In Cam- 
panula aparinoides the structure favours the occurrence of self-pollina- 
tion when there is a lack of insect visitors. In Sabbatia angularis 
(Gentianaceae) there is a very interesting mechanism to secure cross- 
pollination by the agency of insects. Eleocharis mutata (Cyperaceae) is 
proterogynous and anemophilous. 
Autogenetic and Heterogenetic Fertilization^ — Prof. Kornicke 
proposes these terms for the self-pollination and cross-pollination of 
plants ; and adduces instances in which the former phenomenon is to all 
appearance constant and continuous, with abundant fertility, the flowers 
being in some cases open, in others cleistogamous. 
* Bot. Centralbl., xlv. (1891) pp. 161-8, 197-202, 229-34, 261-8, 293-9, 325-9 
(1 pi.). t Biol. Centralbl., xi. (1891) pp. 129-60. 
X Bull. Torrey Bot. Club, xviii. (1891) pp. 111-8. 
§ Yerhandl. Naturbist. Ver. Preuss. Rheinland., xlvii. (1890) Korr.-bl., pp. 
84-99. 
