1897 | CURRENT LITERATURE 219 
mass. A cell plate is formed in the trophoplasm and is split into two new 
plasma membranes before the building of the new cellulose wall. 
Strasburger finds that the oogonium nucleus of Fucus shows the reduced 
number of chromosomes in its first division after the stalk cell has been cut 
off. Centrosomes in the Fucus cell are sharply differentiated, and the spindle 
is formed much as in Stypocaulon. In cell division in the oogonium the cell- 
plate appears first as a layer of granules, each of which divides, and the so 
formed elements fuse to form the bounding membranes of the daughter cells. 
Fusion of the male and female pronuclei and the first division of the fertilized 
egg nucleus are also described. Centrosomes in connection with these 
pronuclei were not observed, but the presence of such a body with the 
antherozoid nucleus is regarded by Strasburger as not improbable. He also 
gives a résumé of the results presented in the different papers, and a more 
theoretical discussion of their bearing on doctrines of cell structure and 
reproduction. 
While zoologists are inclining to the conclusion that the archiplasm of 
Bovéri is only a structurally modified portion of the common cytoplasmic 
mass, the evidence in all the above studies goes to show that there are two 
Substances, kinoplasm and trophoplasm, in the cytoplasm of the plant cell, 
distinct both in structure and chemical composition, and readily distinguishable 
by their visible structure and staining properties. To the kinoplasm falls the 
active work of mitosis, in many cases of cell division. In the ascus It covers 
the entire surface of the young spore, which suggests that the Hautschicht 
may be also kinoplasmic. 
We must conclude, so far as existing evidence is concerned, that there 
are two widely distinct types of spindle formation, the one occurring in ani- 
mals and many of the lower plants, the other in the higher vascular plants. 
In the first the forces of mitosis act in centered systems, while in the other 
the kinoplasmic fibers singly or in bundles are the acting units. 
The work of Mottier and Osterhout serves to emphasize greatly the simi- 
larity between the chromosome figures in anima] and plant cells in the 
So-called heterotypic mitosis. The interpretation of these figures, however, 
remains still in doubt. 
The whole series of studies is of great importance, and a review can do 
it but scant justice. The conclusions reached demand such a readjustment 
of former ideas that real criticism must await further investigation. Any 
theory, however, which differentiates the higher from the lower plants in these 
fundamental cell processes seems likely to have an uncertain tenure, espe- 
Cially as it associates the lower plants with animals. The tendency of investi- 
ation has been to establish similarity rather than diversity in all fundamental 
life phenomena. This objection is purely theoretical, of course, but it is so 
firmly intrenched in the minds of biologists that the proof to the contrary will 
