44 SUMMARY OF CURRENT RESEARCHES RELATING TO 
even morphological equivalent of the centrosome is in these cases in the 
nucleus. Lenhossek acknowledges Mann’s observation of centrosome- 
like bodies in the nuclei of various mammalian nerve-cells, but does not 
see his way as yet to accept the interpretation that they are centro- 
somes. 
Amitosis.* — Dr. O. vom Rath discusses at great length the general 
question of amitosis, having for his particular text its occurrence in the 
glandular cells on the head of Anilocra mediterranea. His general con- 
clusions are (1) that cells which once divide by amitosis never again 
divide by mitosis, they go to the ground, but further amitotic divisions 
may first occur; (2) the number of successive amitoses is narrowly 
limited ; (3) regeneration of cells by amitosis has not been demonstrated ; 
(4) amitosis is especially common in intensely assimilating, secreting or 
excreting cells ; (5) compared with mitosis, amitosis indicates more or 
less marked degeneration, and though simpler, cannot be regarded as the 
primitive mode of division. 
All the cells in gonads which have morula-like or polymorphic 
nuclei are out of the regular developmental line of germ-cells ; they 
gradually go to the ground, but may serve as nutritive material ; the 
mulberry-form of the nucleus indicates that no subsequent mitosis will 
occur. 
Yom Rath goes on to describe the great variety in the shape, size, 
number, and disposition of the attraction-spheres and centrosomes in 
amitotic cells. This variability is perhaps associated with the degene- 
rative character of the cells. He also directs attention to frequent cases 
in which he has observed spheres and centrosomes in the cell-plasma of 
resting cells, and rejects the view that the centrosome has any particular 
relation to nucleolar substance. 
Sympathetic Ganglia of Mammals.j — Prof. A. S. Dogiel has used 
Golgi’s method and a slight modification of Ehrlich’s in the study of the 
ganglia on the gall-bladder of dog and cat, and those of Auerbach’s and 
Meissner’s plexus in guinea-pig, rabbit, rat, and other animals. Among 
his results may be noted that all the cells of the ganglion are associated 
by a plexus of ramifying protoplasmic processes, and that Ramon y 
Cajal’s “ pericellular nests ” have not the importance with which the 
latter credited them. The fine fibres which end with an intercellular 
plexus in the ganglia belong to the sympathetic, and are apparently pre- 
dominantly medullated, but the thick fibres whose terminal ramifications 
form pericellular plexuses in the ganglion are medullated fibres from 
the cerebro-spinal system. 
Cell-Studies, j'— Dr. G. Niessing has studied especially the liver and 
spleen of the salamander, the embryonic liver of man, and the red 
marrow of rabbits. He found the best fixative a mixture of platinum 
chloride 10 per cent, solution, 25 parts ; osmium 2 per cent, solution, 
20 parts ; glacial acetic acid, *05 parts; and fourthly, either distilled 
water 50 parts or concentrated aqueous solution of corrosive sublimate 
50 parts. 
* Zeitschr. f. wiss. Zool., lx. (1895) pp. 1-89 (3 pis.), 
t Arch. f. Mikr. Anat., xlvi. (1895) pp. 305-44 (3 pis.), 
t Tom. cit., pp. 147-68 (1 pi.). 
