ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
615 
C4) Structure of Org-ans. 
External Resemblance of Species.* * * § — Prof. T. Ito calls attention 
to the remarkable resemblance, both in the foliage and in the ripe fruits, 
of Bischoffia javanica , belonging to the Euphorbiacese, to Turpinia 
pomifera, a member of the Sapindaceae, and suggests that the latter 
may obtain some advantage by imitating the appearance of a member 
of a poisonous order. 
Dwarf Habit of Plants.f — M. P. Ganchery contributes an essay on 
“ nanism ” in the vegetable kingdom. His general conclusion is that 
the peculiarities which distinguish the external form and the internal 
structure of dwarf varieties of plants, are, like other characters, depen- 
dent on the environment, and are displayed more strongly in the vegeta- 
tive than in the reproductive organs. A dwarf plant is not a miniature 
of the species with all the organs in the same proportion as in a plant 
of normal size. 
Flower of Onagracese.f — Herr A. Weisse has followed out in detail 
the development of the various whorls of organs in this order ( CEnothera 
biennis ), especially in reference to the formation of the inferior ovary. 
He concludes that the outer wall of the ovary is not a simple structure, 
but is composed, in its peripheral portion of the tissue of the axis, in 
its inner portion of the tissue of the carpels. 
Amphicarpsea monoica.§ — Continuing her observations on this 
heterocarpous Leguminous plant with cleistoganous flowers, Dr. Adeline 
F. Schively gives a more detailed description of both the aerial and 
the subterranean legumes and seeds, and shows, from the result of 
experiments, that one can readily be converted into the other by alter- 
ing the conditions. Although possessing absolutely the same structure 
in the young state, these organs present totally different morphological 
results according as they are exposed to light or to darkness. The 
great ease with which chlorophyll is replaced by anthocyan is one of 
the most remarkable results. It is probable that the purple aerial 
flowers represent the original type. 
Placenta of Primulaceae.|| — From a detailed examination of its 
structure and development in several genera, M. L. Vidal has come to 
the conclusion that the placental column of Primulacem is composed 
of an axial portion and an appendicular portion. In the genera 
Soldanella and Coris the axial portion is elongated to an extraordinary 
extent, and probably serves to assist the pollen-tubes in their way to 
the ovules. 
Mechanism of the Dehiscence of Anthers.lf — A series of experi- 
ments made by Prof. S. Schwendener on the mechanical cause of the 
* Bot. Centralbl., lxxix. (1899) pp. 33-5. 
t Ann. Sci. Nat. (Bot.), ix. (1899) pp. 61-156 (4 pis. and 32 figs.). 
X ‘ Beitr. z. Entwick.-gesch. d. Onagraceen-Blute u.s.w.,’ 1899 (9 pis.). See Bot. 
Centralbl., lxxix. (1899) p. 63. 
§ Contrib. Bot. Lab. Univ. Pennsylvania, ii. (1898) pp. 20-30. Cf. this Journal, 
1898, p. 320. 
|| Journ. de Bot. (Morot), xiii. (1899) pp. 139-46. Cf. this Journal, ante , p. 293. 
f S.B. k. Preuss. Akad. Wiss., 1899, pp. 101-7 (2 figs.) Cf. this Journal, 1898, 
p. 560. 
