ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
141 
nucleus. No swarming motion was actually observed. The phenomena 
of impregnation in Cycas revoluta resemble those of Salisburia adianti- 
folia , and differ from those in all other Gymnosperms at present known 
in this respect, that the pollen-tube does not penetrate deeply into the 
archegone, but remains at some distance from it, even at the time of 
impregnation. It would hence be impossible for the male nuclei to 
impregnate the oosphere were they not previously transformed into 
motile antherozoids. The conveying fluid is supplied by the water 
which is copiously excreted by the female organ at the time of 
impregnation. 
Cross-Fertilisation and Self-Fertilisation. — Prof. A. Borzi* * * § describes 
a type of Epacridese, Cystanthe sprengelioides , which is anemophilous, the 
corolla dropping as soon as it has opened. 
Mr. C. Bobertson f describes the mode of pollination, and the insect- 
visitors, in species of Bhus, Bhamnus, and some other genera. 
In another paper { the same author gives the results obtained from 
the investigation of the genera Hepatica, Asimina, Podophyllum, Solea, 
Euonymus, AEsculus, Astragalus, Stylosanthes, Gymnocladus, Spirsea, 
Gillenia, Viburnum, Symphoricarpos , Aster, Silphium, Heliopsis, Bud- 
beelda, and Cacalia. 
In the Crnciferae there are, according to Herr F. Hildebrand, § all 
gradations between entire self-fertility in Alliaria officinalis and perfect 
self-sterility in Cardamine pratensis. 
Mr. B. Fink || records the results of a series of experiments on cas- 
trating a number of varieties of the tomato, and finds that they are not 
then visited by bees, which seek them for the sake of the pollen. They 
were in all cases readily fertilised by cross-pollination. The period 
required for the pollen-tube to pass through the style after pollination 
is about 12 hours. 
M. J. Briquet^ describes the contrivance for entomophilous pollina- 
tion by bees in Erythronium dens-canis and E. Smithii. 
Degradation and Transformation of Sexual Organs.** — According 
to Herr J. Familler, arrest or transformation of the floral organs takes 
place at various stages of their development ; there may be a great 
difference in this respect even in different flowers on the same plant. 
In the male organ the archespore may remain in its primitive condition, 
although other normal processes of division proceed as usual. In the 
female organ the embryo-sac is often present when the integument is 
greatly reduced. The degradation of pollen is usually indicated by the 
smaller number of grains rather than by their diminished size. Filiform 
staminodes often exhibit a survival of the formation of an anther in this 
early stage. Transformed male organs serve for various purposes, such 
* II Naturalista Siciliano, i. (1896) pp. 65-6. 
t Bot. Gazette, xxii. (1896) pp. 154-65. 
X Trans. St. Louis Acad. Sci., vii. (1896) pp. 151-79. 
§ Ber. Deutsck. Bot. Gesell., xiv. (1896) pp. 324-7. 
|| Minnesota Bot. Studies, 1896, pp. 636-43. 
! Mem. Soc. Sci. Nat. Cherbourg, xxx. (1896) pp. 71-90 (1 pi.). See Bot. 
Centralbh, Ixix. (1897) p. 120. 
** ‘ Biogenetische Unters. iib. verkummerte u. umgebildete Sexual-organe,’ Miin- 
sl.en, 1896, 38 pp. See Bot. Centralbl., Ixviii. (1896) p. 404. 
