766 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Stadmannia , Diplopeltis, Cupania , Araucaria , and Podocarpus ; or the 
growth may be permanently limited, as in the Hippocastanaceae and in 
the embryonal root of Cuscuta. 
Tubercles on the roots of Ceanothus.* * * § — Prof. G. F. Atkinson finds 
that the tubercles on the roots of Ceanothus are caused by a parasitic 
fungus allied to Schinzia ( Franhia ) Alni found upon the roots of Alnus 
and Elseagnus. 
£. Physiology. 
(1) Reproduction and Germination. 
Weismann’s Theory of Heredity.! — Herr W. Burck adduces argu- 
ments, from observations made in the East Indies and elsewhere, against 
the theory of Weismann that the cause of hereditary variability is 
sexual reproduction between different individuals. He finds that 
hereditary modifications often spring up without cross-fertilization. 
Thus in Java there are plants, of which Myrmecodia tuber osa is an 
example, which produce none but cleistogamic flowers; and these 
flowers present special adaptations for self-fertilization combined with 
properties which in other plants serve for the attraction of insects, — a 
white colour, abundant nectar, and proterogyny. The same is the case 
with various species of Anona and other Anonacese. The structure of 
the flowers of Ophrys apifera he regards as originally adapted for cross- 
fertilization, but afterwards modified for self-fertilization. In the case of 
many flowers, such as Aristolochia and Coffea bengalensis, which have 
been relied on as presenting striking illustrations of the necessity of cross- 
fertilization, the author asserts that the indications are quite as strong 
in favour of self-fertilization by insect-agency ; dichogamous flowers are, 
he maintains, as a rule, pollinated from flowers of the same stock. 
Another argument in the same direction is furnished by European fruit- 
trees in Juan Fernandez, which are self-fertilized and abundantly fruitful. 
Function of the Antipodals.!— From an examination of the antipodals 
in the embryo-sac, especially in Ranunculaceae and Graminese, Herr M. 
Westermaier attributes to them a more important function than has 
hitherto been assigned them ; he does not regard them as merely useless 
survivals, but as serving an important purpose in the nutrition of the 
embryo. He arrives at this conclusion from the following considera- 
tions : — Their specific position in the embryo-sac, and the nature of 
their contents ; their anatomical surroundings, and the cuticularizing 
of certain membranes in the ovule ; the mode of distribution of the 
starch within the ovule; there being apparently special contrivances 
for the conduction of starch to the antipodals. In other cases they 
appear to be connected with the formation of the endosperm. 
Reproductive Organs of Phanerogams. § — M. J. Herail gives a 
summary of the present state of our knowledge of the formation of the 
* Bot. Gazette, xvi. (1891) p. 262. 
t Naturk. Tijdschr. Nederl.-Ind., xlix. pp. 501-46 (1 pi.). See Bot. Centralbl., 
1891, Beih., p. 263. 
\ Nova Acta K. Leop.-Carol. Deutsch. Akad. Naturf., lvii. See Bot. Centralbl., 
1891, Beih., p. 111. 
§ ‘ Organes reprod.et formation del’ceuf chez les Phan./ 143 pp. and 1 fig., Paris, 
1889. See Bot. Centralbl., 1891, Beih., p. 272. 
