820 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
spindle-, and uniting filaments, as well as the cell-plate and cytoplasm, 
are erythrophilous. The generative nucleus of the pollen-grain is 
cyanophilous, while the vegetative nucleus is erythrophilous. The 
ovum-nucleus and all the nuclei in the embryo-sac are erythrophilous, 
this character being evident even in the nucleus of the mother-cell of 
the embryo-sac. The phenomena correspond, therefore, altogether to 
those presented by the sexual nuclei of animals.* * * § 
Embryo-sac of Arissema.'j' — Mr. D. M. Mottier describes the various 
stages in the development of the embryo-sac in Arissema triphyllum 
(Aroideae), which do not differ in any material point from the ordinary 
type in Monocotyledons. The mother-cell of the embryo-sac arises as 
a single hypodermal cell in the apex of the nucellus, and divides by 
longitudinal walls into two or three cells. One of these enlarges con- 
siderably, and divides by a transverse wall into two cells ; the lower 
one of these is usually the larger, and absorbs the upper one, developing 
into the embryo-sac. 
Two Endosperms in an Ovule of Pinus.J — Prof. J. B. Farmer re- 
cords the occurrence of two endosperms or prothallia in an ovule of 
Pinus sylvestris. They were separated by a well-marked wall running 
obliquely between them and continuous with the lateral walls of the 
cavity which contained them. The upper endosperm, that nearest tho 
micropyle, was somewhat smaller than the lower, but both possessed 
perfectly developed archegones, and the protoplasm of the central cell 
in each archegone exhibited the frothy vacuolation characteristic of that 
of a normally formed corpuscle. 
Flowers and Insects.§ — Mr. C. Robertson describes the mode of 
insect-pollination in a number of American Umbelliferae. He states 
that in the proterogynous species of this order, the primary umbel con- 
sists only of male flowers, the proportion of hermaphrodite flowers 
increasing in umbels of the 2nd and 3rd orders ; while, on the other 
hand, the proterandrous species commonly have the primary umbels 
composed entirely of hermaphrodite, and the last umbels entirely of 
male flowers. 
Another paper || by the same writer deals with a few American 
species belonging to the Saxifragaceae, Grossulariaceae, Onagraceae, and 
Caprifoliaceae. 
Pollination of Calla palustris.1T —According to Dr. P. Knuth, the 
female flowers of Calla palustris are mature considerably earlier than 
the male flowers in the same spike. The uppermost female flowers 
may be pollinated by male flowers from the same spike ; the lower- 
most must be cross-pollinated, and are in all probability anemophilous ; 
no regular insect visitors were observed. 
* Cf. this Journal, 1891, p. 714. 
t Bot. Gazette, xvii. (1892) pp. 258-60 (1 pi.). 
% Ann. of Bot., vi. (1892) pp. 213-4 (1 fig.). 
§ Trans. Acad. Sci. St. Louis, v. (1892) pp. 419-60. Cf. this Journal, ante, p. 66. 
|| Bot. Gazette, xvii. (1892) pp. 269-76. 
^ Bot. Centralbl., li. (1892) pp. 289-91. 
