714 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
1886, Vejdovsky described the periplast of the male j>ronucleus, its 
division, the appearance of daughter-periplasts, &c. The attractive 
spheres correspond to the periplasts, the central corpuscles to the 
daughter-periplasts. In contrast to Boveri, Vejdovsky regards the 
periplast as a structure arising independently of the sperm-cytoplasm ; 
with daughter-periplasts appearing endogenously within it, it is continued 
in all subsequent divisions of the segmenting ovum. Vejdovsky does 
not believe in the reality of the “ ovo-centrum ” which Fol describes 
as associated with the female pro-nucleus. In the ova of BhjncJielmis at 
least there is no “ marche du quadrille.” 
B. Histology. 
Difference between the Nuclei of Male and Female Reproductive 
Elements.* — Prof. L. Auerbach has studied the male and female repro- 
ductive organs and elements of Cyprinus Carpio , Esox Indus , Triton 
tseniatus, Bana temporaria, Lacerta agilis, Gallus domesticus, &c., and 
after subjecting sections and preparations to the same technical treat- 
ment, finds that the sex-elements differ in nuclear characters. The 
head of the ripe spermatozoon consists entirely of cyanophilous sub- 
stance ; the tail and the intermediate portion are erythrophilous. In 
the ova the germinal vesicle is distinctly erythrophilous, and the nucleoli 
especially so. The same is true of yolk-granules, and of the cell- 
substance of follicular epithelium. But the substance of the ovum, and 
the outer layer of the vitelline membrane in the carp’s ova, are more or 
less amphichromatic, sometimes reddish, sometimes bluish. As the head 
of the spermatozoon and the germinal vesicle of the ovum are the most 
important parts of the reproductive cells, it may be said that the male 
fertilizing-stuff is cyanophilous, while the complementary female-stuff 
is erythrophilous. And as the yolk-corpuscles are also erythrophilous, 
this characteristic is preponderant in the female germinal substance. 
Thus there is a qualitative nuclear difference between the male and the 
female reproductive elements. 
Structure and Division of the Cell.f — Prof. W. Flemming has made 
a fresh study of epithelial, endothelial, and similar cells from larval 
salamanders. In division he finds traces of what seems to represent a 
cell-plate, such as occurs in plants and in some Invertebrates. He calls 
attention to a change in the cell-substance during mitosis — a peripheral 
thickening and the appearance of a clear loose internal stratum around 
the nucleus. He then gives a full account of what he has observed in 
regard to the attraction-spheres and central corpuscles in leucocytes 
and other cells, adding some observations to what was previously 
communicated. 
The greater part of the present memoir is devoted to a discussion of 
cell-division and the origin of the spindle. The rudiment of the central 
spindle lies outside the nucleus, but Flemming cannot admit that the 
greater part of the spindle-fibres is due to extra-nuclear material. He 
is more inclined to believe that it is due to the linin-substances and 
membrane of the nucleus. But the spindle may well have a double origin. 
* SB. K. Preuss. Akad. Wiss., 1891, pp. 713-50. 
f Archiv f. Mikr. Anat., xxxvii. (1891) pp. 685-751 (3 pis.). 
