1896] CURRENT LITERATURE 427 
their place to form the nuclear plate. In the resting stage the primary 
nucleus of the embryo-sac has the vegetative characters, but as division 
approaches the chromatin thread contracts to one side of the nuclear cavity, 
the nucleolus partially dissolves, and there is also a partial disappearance of 
the nuclear membrane. The nucleoli and membrane reappear in the spirem 
stage. The spirem of the embryo-sac nucleus differs decidedly from the 
vegetative type. The ribbon of the vegetative spirem stains like chromatin, 
but in this spirem there is an erythrophilous ribbon bordered by chromatin. 
Longitudinal fission of the entire ribbon takes place before segmentation into 
the lengths which become the chromosomes. The nuclei resulting from the 
second and third embryo-sac divisions resemble the primary nucleus in the 
staining of the ribbon, but otherwise they follow the vegetative type. After 
the second division the lower antipodal nucleus divides by the direct method. 
The number of chromosomes in vegetative nuclei is generally about 
twenty-four; in the primary nucleus of the embryo-sac, twelve; but after its 
first division the micropylar nucleus has twelve, while the antipodal may 
have from twenty to thirty-two. Throughout the oogenesis twelve chromo- 
of the sac, but 
in the antipodal end the number varies from twenty to thirty-four. The 
transverse division of chromosomes, which Dr. Haecker suggested might 
precede the formation of the sexual nucleus, does not occur.—C. J. ©. 
coca data, and in part upon critical deduction 
Additional papers on the same subjects are in course 
Pees already upon the table are of sufficient importance 
attention, 
_ His initial study, the mechanism and procedure of tendrils by which 
coiling is effected, has given, perhaps, the most important results.® Begun in 
the physiological laboratory of Purdue University in 1891, and continued as 
Sccasion permitted since, it has illuminated a number of obscure points, an 
done much toward making the whole matter of tendril movement under- 
e to merit present 
dri ; ; 
til, a function of maturity, and the sensitive resp 
dec ee Senetalization is especially helpful that ® ¢ 
€pendent upon rapidity for effectiveness are only indire 
t 
lass of plant movements 
ctly associated with 
. * —I 30. 
*For the earlier papers see this journal 17: 205~212- pl. 14. 18923 ais ae “ 
93; and Bot. Centralblatt 66:145, 140. The recent Gow) ee 
k Windungs f 
3 ture 0 
bot. Gesellschaft 14 :151-154. 1896, and Loe 
re did, 
te 1 ” 
narils,” Annals of Botany 10: 373-402. Al. 79: 1896. 
