454 Hartog . — The Alleged Fertilization 
are, in any case, essentially different from all those formed 
by repeated nuclear fission in the previous life-history of 
the plant. . . . Obviously such endogamous nuclear unions 
cannot occur in plants with distinct walls partitioning them 
into distinct cells. But we do find parallel cases in other 
apocytial plants. In the Dasycladeae the nuclei fuse several 
together in a gametangium, and round the single fusion-nuclei 
the protoplasm aggregates to form uninuclear [isogamous] 
gametes which pair with those of other plants. In Dcrbesia , 
zoospores with fusion-nuclei formed in precisely the same 
way have apparently lost the faculty of pairing, and develop 
directly. ... In Uredineae the teleutospore is bicellular; in 
each cell the nucleus divides ; and then in the cell the two 
sister- nuclei fuse again, so that each of the two resting-spores 
of which the teleutospore is formed has a fusion-nucleus. 
And in Ustilagineae each spore is primitively binucleate ; 
but becomes uninucleate by the fusion of the nuclei. ... I refer 
also to the formation of the large “basidial nucleus ” of the 
Basidiomycetes by the fusion of two or more ; from this, by 
two bipartitions, are formed the nuclei for the basidiospores. 
In most animals the ovarian egg divides at maturity into 
a brood of four, three of which are functionless and are termed 
polar bodies ; while the fourth is the functional oosphere 
which is usually fertilized by the male cell, the spermatozoon. 
In several cases of so-called parthenogenesis the second cell- 
division remains incomplete : the cell-nucleus divides as if to 
give rise to the nuclei of a polar body and an oosphere 
respectively ; but then the former nucleus moves back and 
fuses, playing the part of a male [I should rather have written 
‘ the same part as the sperm-nucleus ’] with its sister, just as we 
have seen in the Uredineae/ These facts I quoted especially 
from Boveri and Hertwig in ’91 ; but since then Brauer of 
Heidelberg confirmed them in the fullest way for Artemia ; 
and Wilson’s ‘Cell in Development and Inheritance ’ (where 
they are quoted with figures) should be familiar to every one 
who, like Professor Trow, proposes to deal with questions 
of cytology. 
