70 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Mr. W. F. Ganong finds that the various modifications in the external 
conformation may he referred back to a few, or even to a single funda- 
mental form. Transitional forms between leaves and spines occur in 
Opuntia and Echinopsis , showing that the latter are modified leaves. 
Each leaf has a single axillary hud ; hut in some genera the growing 
point is elongated and bifurcates ; this is not the result of branching, 
but of the formation of a permanent tissue between two divisions of the 
growing points. The sheath of the spines in Opuntia is formed of viscid 
hairs. Some species of Cereus , Opuntia , Bhipsalis, and Mamillaria pos- 
sess honey-secreting structures, which are always metamorphosed spines. 
A scheme is appended of the relationship of the various genera of the 
order. 
Morphology of Cabombese and Nymphseaceae. — M. M. Raciborski* * * § 
adds some further details to his account of the structure of these natural 
orders. The cells of the rhizome of Brasenia contain a crystalline sub- 
stance (brasenin) which is organic, and appears to belong to the series 
of oils. The tannin which abounds in these plants is apparently an 
excretory product, and has very little, if any, function in the way of pro- 
tection. The mucus which clothes the intercellular spaces displays 
none of the reactions of protoplasm. 
Herr K. Schumann "j* differs in some points from Raciborski’s mor- 
phological interpretations, and lays much more stress on the effect of 
contact in producing certain morphological peculiarities. 
j8. Physiology. 
Cl) Reproduction and Embryology. 
Cross- and Self-Pollination. — -According to Dr. P. Knuthf the 
flowers of Lonicera Periclymenum are strongly proterandrous, and are 
not self-pollinated. They owe their pollination to night-flying moths, 
especially Sphingidse, which visit them abundantly. 
In Lonicera japonica, according to Mr. T. Meehan,§ the flowers are 
self-pollinated, but usually infertile. Bees obtain much more honey 
from the fallen withered than from the living flowers. 
Mr. P. H. Mell || records the results of a series of observations on 
the intercrossing of different varieties of the cotton-plant, which he finds 
distinctly advantageous in increasing the strength of the fibre. The 
cotton-plant is pollinated by the agency of the wind and of insects. It 
is remarkable for the rapid growth of the pollen-tube. 
Mr. A. G. Hamilton! describes the arrangements for effecting cross- 
pollination in Clerodendron tomentosum and Candullea serrulata. The 
former is proterandrous, and is pollinated by a night-flying moth Deile 
phila celerio. The latter is also strongly proterandrous, and is not self 
fertile. The pollination is effected by bees, through the agency of the 
strongly irritable column. 
* Flora, lxxix. (1894) Ergiinzungsbd., pp. 92-108 (1 fig.). Cf. this Journal, 
1894, p. 588. t Ber. Deutsch. Bot. Gesell., xii. (1894) pp. 173-8. 
f Bot. Centralbl., xl. (1894) pp. 41-4 (3 figs.). 
§ Trans. Acad. Nat. Sci. Philadelphia, 1894, pp. 169-71. 
'll Agricultural Exper.-Stat.., Auburn, Ala., Bull. No. f56, 1894, 47 pp., 4 pis. and 
5 figs. t Proc. Linn. Soc. N.S. Wales, ix. (1894) pp. 15-24 (1 pi.). 
