ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
199 
BOTANY. 
A. GENERAL, including the Anatomy and Physiology 
of the Phanerogamia. 
a. Anatomy. 
(1) Cell-structure and Protoplasm. 
Energids and Cells. * — Pursuing his investigations on the subject of 
energids, Prof. J. Sachs insists on the essential distinction between the 
idea of an energid and that of a cell. The former term denotes solely 
the living body endowed with energy, in contrast to the bodies which 
are found outside it (cell-walls) or inside it (starch-grains, aleurone- 
grains, crystals, &c.). These structures do not belong to the energid, 
and hav T e no, or only a potential energy. If they serve for the nutrition 
of the energid, and the building up of its substance for the purpose of 
multiplication, this takes place only through the energy of the energid 
itself. These substances may therefore be regarded as passive products 
of the energid. 
In the more highly differentiated energids there are to be distin- 
guished ; — the nucleus, with its ground-substance and nuclein, together 
with the centrosomes and nucleoles; and the protoplasm, with its 
cliromatophores. To the nuclein or chromatin appears to belong the 
special energy belonging to new formations; while the energy of 
chlorophyll is more directly connected with nutrition. So numerous 
are the phenomena connected with protoplasm, that it is difficult to 
assign to it its characteristic function. The cell may be defined as a 
cellulose-chamber inhabited by an energid. 
The author regards the term “ organised ” as misapplied to such a 
substance as starch, which has no vitality without the co-operation of 
an energid. The parts of an energid are not ephemeral, like starch- 
grains, but constitute the embryonal substance, the carrier of heredity ; 
they render possible the continuity of generations ; it is in them that 
the ontogenesis of individuals and the phylogenetic connection of species 
and types are fulfilled ; and this is accomplished by the energids through 
the fact that they are multiplied exclusively by intussusception, not by 
apposition, like cell-walls, starch-grains, and crystals. The production 
of a new mass of protoplasm presupposes the previous existence of other 
masses of protoplasm. It is only on this supposition that the idea of 
heredity is possible. Isolated masses of protoplasm, if they contain a 
nucleus, will envelope themselves with cellulose and continue to grow. 
Hence each nucleus, with the portion of protoplasm which surrounds it, 
is an energid. In the Coeloblastae we do not find the sharp separation 
of adjoining energids which occurs in the Metaphytes. 
The author concludes with some further remarks on the connection 
between his energid theory and heredity. 
Nuclei and Nucleoles in Merismatic and Sporogenous Tissues.j — 
Ilerr F. Rosen has studied the behaviour of the nucleus and nucleoles 
* Flora, lxxxi. (1895) Erg'anz -Bd., pp. 405-34. Of. this Journal, 1892, p. 381. 
t Beitr. z. Biol. d. Pflanzen (Cohn), vii. (1895) pp. 225-312 (3 pis. and 8 figs.). 
p 2 
