KARYOKINESIS AND ITS RELATION TO FERTILIZATION. 251 
aster). In the same way as the directive corpuscles the sper- 
matozoa are extruded from a mother-cell, and the mother-cell, 
comparable to the egg-cell, remains behind; here, too, a 
formation of amphiasters occurs. Thus in both reproductive 
cells (“ gonoblasts”’ of Minot) there occurs the same striking 
phenomenon of the appearance of two cellular elements, 
accompanied by very marked karyokinetic processes ! 
Now, says Minot, since in the one case the large persistent 
cell is female, we are led to conclude that also the remnant of 
the sperm mother-cell is female; and since, further, the 
extruded sperm-forming cells are male, we may argue for the 
male nature of the directive corpuscles. Minot draws a 
parallel, therefore, between the directive corpuscles of the egg 
and the spermatozoon ; and herein differs from van Beneden, 
who has regarded as the directive corpuscles in sperm-formation 
those structures which were above spoken of as “ corps resi- 
duels.” Minot yet further arrives at conclusions as to the 
bisexuality of the cell, by the simple reflection that, since 
Martin Barry’s time, we have become acquainted with the 
union during fertilization of egg and spermatozoon; conse- 
quently the fertilized egg must be hermaphrodite. From this all 
other cells arise by division, therefore these are also hermaphro- 
dite. Minot’s idea is interesting and logically consistent, not- 
withstanding that it lacks conclusive facts as a basis ; it is simply 
a deduction from the presence of the directive corpuscles, and for 
these a series of other meanings is admissible. But if E. van 
Beneden’s observations are rightly interpreted, a surer support 
is given to the bisexual nature of the two first segmentation- 
spheres, and thereby amore significant advance is made. E. van 
Beneden must therefore, without any doubt, be regarded as 
the real founder of the doctrine of the bisexuality of cells. 
Minot also says with reason that, on the ground of the 
1 With regard to the hermaphroditism of cells, the reader should compare 
Sabatier (175). By him the germinal vesicle is represented as the female 
element of the egg-cell; the follicle cells, which, according to Sabatier, are 
formed by the egg, are regarded as the male element. The spermatozoa of 
the Decapods studied by him arise in large cells, the “ protospermatoblasts,”’ 
and are homologous with the epithelial cells of the Graafian follicle, 
