50 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
finds nothing that deviates widely from what has been observed in other 
Dicotyledons. The embryo-sac is derived from the lowest of the four 
cells resulting from the division of the archcsporc. The reduction in 
the number of chromosomes appears to take place in the archespore, the 
morphological equivalent of the pollen-mother-cell. After the embryo- 
sac has divided, the sac doubles in both length and breadth. A peculi- 
arity observed in Aconitum was the great increase in size and the perma- 
nence of the antipodals, which completely fill up the beak-like lower 
part of the embryo-sac. They probably play an important part in the 
nutrition of the embryo. The nuclei of the antipodals, of the egg-appa- 
ratus, and of the two pollen-nuclei, each possess a single nucleole, those 
of the antipodal-nuclei being comparatively large. 
Two cases of polyembryony were observed, both indicating that the 
synergids are degenerated egg-cells or archegones which still retain the 
potentiality of being impregnated. The mode of primary division of the 
embryo, up to its 3- or 5-celled condition, varies in different individuals. 
The division of the primary endosperm-nucleus may be completed before 
the fusion has taken place of the sperm-nucleus with the ovum-nucleus. 
Hermaphroditism in Mercurialis and Cannabis.* — From a number 
of examples of inflorescence in the hemp which partook partly of a male, 
partly of a female character, M. M. Molliard draws the following con- 
clusions. The perianth of the female flower is homologous to the calyx 
of the male flower. The flower is fundamentally unisexual. The pistil 
is composed of two carpels. Pollen-mother-cells may develope after the 
fashion of embryo-sac-mother-cells. The sex is not absolutely deter- 
mined in the seed, but may be modified by abnormal conditions. A 
transformation may be observed from male to female infloreseences under 
conditions that are very unfavourable to the development of the vegeta- 
tive organs, especially under the influence of a feeble illumination. 
Similar results were obtained with Mercurialis annua. 
Determination of Sex in Plants.f — Carrying on his researches on 
this subject, M. M. Molliard now states that, in the case of Mercurialis 
annua , a high temperature favours the production of female individuals. 
Whether the action is simply one of promoting especially the germina- 
tion of female seeds, or whether it incites an actual change in the seeds 
themselves, is at present undetermined. 
(2) Nutrition ancl Growth (including 1 Germination, and Movements 
of Fluids). 
Laws of Growth f — Sig. L. Montemartini has studied the phenomena 
of growth of the apices of shoots, especially in plants with opposite 
leaves, e.g. Cannabis , Bicinus, and Selianthus. It is frequently the case 
that a larger number of internodes develope in one period of growth 
than the number in the bud at the commencement of that period. The 
activity of the meristem in the apex obeys a law of periodicity of its 
own, independent of the external conditions under which the meristem 
is developed. 
* Rev. Gen. de Rot. (Bonnier), x. (1898) pp. 321-34 (13 figs.), 
t Comptes Rendus, cxxvii. (1898) pp. 669-71. Cf. this Journal, 1898, p. 100. 
t Atti 1st. Bot. r. Univ. Padova, 1898, 69 pp. See Bot. Centralbl., lxxvi. (1898) 
p. 273. Cf. this Journal, 1897, p. 409. 
