178 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
tube follows tbe same course as in typical chalazogamous types. No 
special conducting or nutritive tissue for the pollen-tube occurs in the elm. 
The phenomena appear to exhibit a tendency to abandon the primitive 
chalazogamic in favour of the later acquired porogamic habit. In this 
respect they stand on a par with those in Cannabis* Fertilisation takes 
place on the third or fourth day after pollination. The embryo-sac fre- 
quently displays anomalies, e.g. in the number of antipodals. 
Embryogeny of Allium.f — Mr. C. J. Elmore has followed the de- 
velopment of the embryo in several species of Allium (chiefly tricoccum , 
cernuum, and canadense), with the view of determining the probability of 
the occurrence of polyembryony. Out of 75 embryo-sacs of A. tricoccum, 
only 16 contained antipodal cells; and in 95 of A. cernuum, there were 
only 29 with antipodals. When antipodals were present, they were but 
feebly developed ; and there was no evidence whatever of any tendency 
on their part to develop into embryo-sacs ; they had usually disappeared 
at an early stage of development. 
Embryology of Alyssum.i — The following are the more important 
conclusions attained by Lumina C. Riddle from a study of the develop- 
ment of the embryo-sac in Alyssum macrocarjpum. The hypodermal arclie- 
sporial cell divides into a tapetal cell and a megaspore-mother-cell, the 
latter giving rise to four megaspores, three potential megaspores, and a 
“ vital ” megaspore which developes into the embryo-sac. The antipodals 
disappear during the early stages of the development of the embryo. 
The endosperm appears soon after the fertilisation of the oosphere. The 
number of cells in the suspensor varies from 6 to 15 ; the number 
beyond 6 apparently depending on the number of intercalary divisions, 
some of which may be longitudinal. The endosperm lines the entire 
embryo-sac with a single layer of cells, but is more abundant round the 
young embryo, and forms a peculiar growth in the antipodal region. 
C2) Nutrition and Growth, (including- Germination, and Movements 
of Fluids). 
Metastasis in Halophytes.§ — By a halophyte Herr L. Diels under- 
stands a plant that has the power of decomposing chlorides so as to 
make them innocuous. He found that when such plants are grown in 
distilled water, or in water almost free from salts, the percentage of 
sodium chloride contained in them diminishes. This is accompanied 
by an increase in the amount of malic acid ; but the nature of the chemi- 
cal process is not clear ; it seems probable that the chlorine combines 
with hydrogen, and is excreted through the root. This increase of 
malic acid is rendered possible from the diminished transpiration re- 
sulting from the xerophilous structure of halophytes, especially the 
reduction of the stomatic apparatus. 
Chlorophyll Assimilation of Liniodorum abortivum.|| — This terres- 
trial orchid is regarded by M. E. Griffon as intermediate between those 
which have green leaves and which also possess a mycorhiza, like many 
* Cf. this Journal, ante , p. 47. 
t Bot. Gazette, xxvi. (1898) pp. 277-8. J Tom. cit., pp. 314-24 (3 pis.). 
§ Jahrb. f. wiss. Bot., xxxii. (1898) pp. 309-22. 
|| Comptes Rendus, cxxvii. (1898) pp. 973-6. 
