438 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
uncommon in a hybrid double Petunia. The following is bis explana- 
tion of the morphology. The anthers have, between their pollen-sacs, a 
special tissue which assists their dehiscence by its gelatinisation. The 
nectaries have the morphological value of carpels. When a stamen is 
developed within the ovary, it corresponds, not to an entire leaf, but only 
to a portion of a leaf. A pollen-sac may replace the embryo-sac within 
the ovule ; and all stages of transition may be observed between an 
ovule and an anther-lobe. The only universal law which governs the 
formation of the nutrient layer in the anther is that its cells become 
differentiated around the mother-cells of the pollen-grains. 
( 2 ) Nutrition and Growth (including' Germination, and Movements 
of Fluids). 
Effect of the Rontgen Rays on Germination.* * * § — Herr A. Schober 
has experimented on the effect of the X-rays on the germination of the 
oat, and concludes that they differ from the ordinary light-rays in this 
respect also, that they have no power of producing heliotropic curvatures, 
even in organs so sensitive to light as the axis of a young seedling. 
Germination of the Cocoa-nut. t — Herr L. Wittmack has followed 
out the early stages in the germination of the cocoa-nut, and has added 
some items to our previous knowledge of the subject. The absorbing 
organ has a fungus-like appearance, consisting of an obconical stalk, and 
a nearly hemispherical head which contains vascular bundles imbedded 
in a large-celled spongy parenchyme. This organ conveys to the 
originally very small embryo the food-material, which it absorbs first 
from the milk and then from the endosperm ; but the statement usually 
made, that the ripe cocoa-nut contains no milk, is erroneous. 
Germination of Xanthium.f— Prof. J. C. Arthur states that the two 
seeds contained in the fruit of the “ cocklebur,” Xanthium canadense and 
strumarium , do not lie side by side, and that they do not germinate at 
the same time, one being delayed for a whole season after the other, 
apparently for the purpose of promoting distribution. The same phe- 
nomenon is popularly attributed to the two seeds of the spikelet of the 
wild oat, Avena fatua, but the author’s observations do not tend to 
confirm this. 
Correlation in the Growth of Different Organs.§ — Dr. F. Hering 
has experimented on the effect on the growth of certain organs of plants 
of the suppression of the growth of other organs by mechanical con- 
trivances ; and has come to a somewhat different conclusion from that of 
Kny,|| that the growth of roots and shoots proceeds with a high degree 
of independence. When either the root or the shoot-system was encased 
in plaster of Paris, he found a retardation of growth always to take place 
in the system not so enclosed. In Streptocarpus it is usual for one only 
of the cotyledons to attain considerable dimensions, while the other 
* Ber. Deutsch. Bot. Gesell., xiv. (1896) pp. 108-10. 
t Tom. cit., pp. 145-50 (2 figs.). 
X Proc. Ann. Meeting Soc. for Promotion of Agric. Sci. (Springfield), 1895, 
pp. 70-9 (2 figs.). 
§ Jahrb. f. wiss. Bot. (Pfeifer u. Strasburger), xxix. (1896) pp. 132-70 (4 figs.). 
|| Cf. this Journal, 1895, p. 71. 
