ZOOLOGY AND BOTANY* MICROSCOPY, ETC. 
47 
BOTANY. 
A. GENERAL, including the Anatomy and Physiology 
of the Phanerogamia. 
a. Anatomy. 
(1) Cell-Structure and Protoplasm. 
Respiratory Function of the Nucleus.* — In further notes on the 
process of nuclear division, M. C. Degagny lays stress on the fact that 
(in Spirogyra and Liliurn candidum) during the formation of the nuclear 
plate, the length of the spindle is reduced by one-half. The energy re- 
quired for this contraction has its origin in the respiration of the cell, 
the seat of this respiration being the outer threads of the spindle and the 
adjacent parts of the cytoplasm. The filaments do not merely contract, 
but become at the same time rigid and tetanised. They subsequently 
lose their rigidity, and the phenomena attending these processes are de- 
scribed in great detail. The principal function of the nucleus during 
division appears to be to prepare a substance destined for respiration ; 
this protoplasmic substance, capable of easy digestion and of contracting 
while respiring, is furnished by the fine filaments of the spindle. In 
Lilium candidum, owing to the enormous mass of protoplasm which fills 
the embryo-sac, respiration is greatly reduced in the central part. In 
Spirogyra, on the other hand, where the nucleus is in immediate relation 
with the external medium, it is much more evident. 
Vegetable Cytology .f — In a new work on the morphology and physio- 
logy of the nucleus in plants, Prof. A. Zimmermann gives a summary 
of all the more important recent observations in this subject. The book 
is divided into three main parts ; the first dealing with technique, and 
with the chemistry and physiology of the nucleus in general ; the second, 
with the structure and behaviour of the nucleus in the different groups 
of the vegetable kingdom, including its history in fertilisation and em- 
bryogeny ; while the third part consists of a copious bibliography. 
Prof. J. B. Farmer J gives an account of the more important ad- 
vances recently made in the study of Vegetable Cytology. He lays 
stress on the fact that the two methods — microchemical and staining — 
should both be employed. While the staining exhibits more or less 
completely the structural arrangement of the substances present, the 
microchemical method not only indicates some at least of the important 
differences which exist between the different structures revealed by the 
action of staining, but it teaches us that certain of these same structures 
are by no means so homogeneous in their nature as one might be led to 
suppose from the evidence derived from staining alone. 
* Bull. Soc. Bot. France, xliii. (1896) pp. 310-4, 332-16. Cf. this Journal, 1896, 
p. 535. 
f ‘ Die Morph, u. Phys. d. pflanzischen Zell-kernes,’ Jena, 1896, 188 pp. See 
Nature, lv. (1896) p. 147. 
X Science Progress, v. (1896) pp. 22-37 ; i. (1897) pp. 141-66. 
