1104 The American Naturalist. [December, 
zogamy in Juglans regia. The large ovule is anatropous. The pla- 
centa fills the ovary and frequently fuses with it. From the sides of 
the placenta develop two peculiar wing-like growths projecting some- 
what above the base of the ovule. The pollen tube is strictly intercel- 
lular in its growth as in the other Chalazogamia. After the tube has * 
penetrated the stigma and grown through the style, it enters the tissue 
of the ovary near the canal of the style but without entering its cleft 
or penetrating the micropyle. During its further growth, in the wall 
of the ovary, the tube turns to right or left and passing through the 
wing-like placental growths enters the top of the placenta and from 
here grows through the chalaza into the nucellus and to the embryo 
sack. During nearly its entire growth the tube sends out projections 
and in the chalazal- region these become branches which give to the 
nucellus a veined appearance as if penetrated by a number of distinct 
pollen tubes. Several of these branches finally reach the embryo sack 
and surround it on all sides. The author detected the male nucleus, 
not only in the pollen tube, but also inside the embryo sack. At this 
time there was in the embryo sack neither an egg apparatus nor a dif- 
ferentiated egg. Besides the antipodal cells, separated from each 
other by a cellulose membrane, there were only some free nuclei on 
which devolved the rôle of the female apparatus. These appearances can 
hardly be explained otherwise than by supposing that the male nucleus 
fuses with one of the female nuclei to form the egg-cell. In these par- 
ticulars Juglans (also Corylus) appears to be related to Gnetum, the 
developmental history of which has been studied critically of late by 
Geo. Karsten (Coheen’s Beiträge, VI). The author now attributes 
chalazogamy to the inability of the pollen tube to grow through empty 
spaces, and regards these plants as standing on the threshhold of the 
angiospermous world. To him they represent transition forms be- 
tween Gymnosperms in which the pollen tube has an intercellular 
growth and Angiosperms in which it grows through the mycropyle.— 
Erwin F. SMITE. 
ZOOLOGY. 
Variation in Halicystus octoradiatus.—Among 154 speci- 
mens, according to a recent paper in the Quarterly Journal of Micro- 
scopical Science,| Mr. E. T. Brown found 120 normal and 34 abnormal 
Vol. XX XVIII, pp. 1-9, PL. I. 
