294 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
attraction sphere and its centrosome. In the centre the cytomitome and 
the linin-framework of the nucleus are united. 
Mechanism of Cell-Division.* — Dr. L. Driiner has studied this in 
the testes of the Salamander, which have served so many investigators 
as suitable objects. Unable to accept Flemming’s conclusion that the 
divergence of the poles is due to a centrifugal shortening of the polar 
rays, Driiner inquires afresh into the forces by which the central 
corpuscles are separated, and are kept in position at the time of the 
strongest tension of the mantle- fibres. Apart from the polar rays, there 
are two other sets of fibres proceeding from the poles, namely — the 
fibres of the central spindle (central fibres) which run continuously from 
pole to pole, and the fibres of the spindle-mantle (mantle fibres) which 
are attached to the halves of the chromosomes. The mantle-fibres alone 
are contractile. The central spindle-fibres exhibit elasticity, for they 
are bent by polar pressure and they straighten when released from this. 
They keep the poles apart against the action of the contractile mantle- 
fibres. The polar fibres have no contractility, but by their growth they 
displace the pole towards the cell-membrane. In fact, the author speaks 
of both central spindle and polar rays as Stiitzorgane. Of much interest 
is the chapter entitled “ An attempt towards a comparative morphology 
of cell-division.” 
Nuclear Structure and Division.! — Dr. 0. Van der Stricht describes 
irregularly contoured and lobed nuclei in some of the epithelial cells of 
larval Salamanders. The peculiarity of shape appears to be associated 
with the last stage of mitosis, during the final reconstruction of daughter- 
nuclei. Other cases of nuclear polymorphism are also discussed. 
Wandering Cells of the Frog.f — Dr. A. A. Kanthack and Mr. 
W. B. Hardy find that the three different kinds of wandering cells, the 
eosinophile cell, the hyaline or non-granular cell, and the basophile rose- 
reacting cell, proliferate while free in the body fluids. The different 
kinds of cells multiply independently, so that the numbers of any one 
kind of cell may vary without a corresponding variation in the numbers 
of the other cells. The three kinds are differently affected by different 
substances introduced into the plasma. For example, solid substances 
of indifferent nature affect only hyaline cells, which ingest the particles. 
Anthrax and filamentous bacilli, when first introduced, attract only the 
eosinophile cells, which kill or maim them by means of a substance 
derived from their stored eosinophile granules. After the bacilli have 
been thus acted on they can become the prey of the hyaline cells. 
Vermilion and yeast cells attract both hyaline and eosinophile cells. 
The rose-reacting cells are increased in number and size by alteration 
in the chemical composition of the plasma. It is pointed out that the 
eosinophile cells are highly specialised bodies endowed with the power 
of movement and with glandular powers directed to the production of a 
bactericidal or at least antitoxic substance. With regard to the 
morphology of these cells the authors point out that the sporadic 
mesoblast of the frog contains elements precisely similar to those that 
* Jenaische Zeitsclir. f. Naturwiss., xxix. (1894) pp. 271-344 (5 pis.). 
f Bull. Acad. Belg., xxix. (1895) pp. 38-58 (1 pi.). 
X Phil. Trans., clxxxv. B. (1894) pp. *279-318 (1 pi.). ; 
