ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
329 
BOTANY. 
A. GENERAL, including the Anatomy and Physiology 
of the Phanerogamia. 
a. Anatomy. 
CD Cell-structure and Protoplasm. 
Division of the Nucleus.* — M. C. Degagny has studied the pheno- 
mena attending the disappearance of the nuclear membrane in the 
process of division, especially in Spirogyra and in the embryo-sac of 
Lilium. This disappearance is common to all nuclei, whether animal 
or vegetable. The processes referred to take place with great rapidity ; 
but the observations of the author indicate that they are not due 
to the directing spheres. At the moment when the rods are being 
formed, the nucleus contains a large quantity of granulations and of 
hyaline protoplasmic substances, among which are found a portion of 
the rods in the upper part of the nucleus ; its lower portion, towards the 
funicular bundle, contains a denser nuclear fluid in which the other 
rods are to be found. The granular protoplasm then becomes uni- 
formly disseminated through the nucleus, enveloping all the rods as 
well as the nucleole. The protoplasm next disappears, and is re- 
placed by innumerable achromatic filaments, which pass in every direc- 
tion through the nuclear cavity, now deprived of its membrane. The 
granular protoplasmic substances which have enveloped the nucleole 
and the rods have been transformed into achromatic filaments, this 
transformation taking place at the moment when the nuclear fluid 
which surrounds the rods has become denser. This process is then 
carried on to the membrane, causing at length its dissolution. A 
similar change has, in the meantime, also taken place in the filaments 
and in the nucleole. The nuclein can only act on a very dense medium. 
Generally speaking, the membrane is completely transformed, but the 
products of its dissolution no longer form achromatic filaments ; the 
substances which compose it are less profoundly modified ; they form 
granulations which are added to those of the neighbouring cytoplasm. 
Nuclear Division in the Anthers of Lilium. f — Professor J. B. 
Farmer has pursued his investigation of this subject in three species of 
Lilium, L. candidum , speciosum , and tigrinum. As fixing solutions he 
recommends absolute alcohol, alcohol and acetic acid, alcohol and formic 
acid, and especially Hermann’s solution. He does not accept the 
criticism of Humphrey J that the results which he previously obtained 
are the result of pathological conditions. 
When the end is approaching of the first division of the nucleus, 
the chromosomes are arranged regularly in relation to the polar field, 
but do not enter their period of rest until after the next division. The 
combining filaments give rise to the barrel-like structure, and the cell- 
* Bull. Soc. Bot. France, xli. (1895) pp. 588-96. 
t Flora, lxxx. (1895) pp. 56-67 (2 pis.). Cf. this Journal, 1894, p. 74. 
% Cf. this Jourual, 1894, p. 583. 
