496 Harper—Nuclear Phenomena in the Smuts. 
which Hertwig and Strasburger have pronounced the essential 
feature in sexual fusions in both plants and animals is lacking. 
None the less we have, at least in the pairing of the conidia of 
the anther smut, a phenomenon which shows some of the physio¬ 
logical results which accompany a true sexual fusion, namely, 
increased metabolism and increased capacity to resist unfavor¬ 
able external conditions. And in all the cases mentioned an im¬ 
proved physiological condition may be fairly assumed as a re¬ 
sult of merely cytoplasmic fusions. How it is that a cell finds 
itself in better condition as a result of increasing its mass by 
fusion with a second cell, is not clear except where the increased 
size is a necessity in order to reach a certain position necessary 
for the further development of the organism, as in the case of the 
germ tubes of Nectria or Sclerotinia described above. Such an 
advantage is not, however, present, in the fusions of the anther 
smut. If reduction of volume and consequently of exposed sur¬ 
face for osmosis followed the fusion, as is the case in so many 
true fertilizations, an advantage might be assumed to exist in 
this diminution of surface contact with unfavorable surround¬ 
ings and the greater density of the protoplasmic mass; but in 
the anther smut fusion is followed by a very notable increase 
in the size of the fused cells. It is impossible at present to say 
wherein the significance of this fusion consists. It may be that 
the phenomena are to be interpreted as a primitive type of sex¬ 
ual union, where the process of fusion has not yet gone so far 
as to include a union of the nuclei and a loss of individuality 
of the gametes; or it may be a degenerate form of sexuality in 
which the nuclear union has been lost and the cytoplasmic un¬ 
ion retained. 
There can be no doubt, however, that such cases show clearly 
that there is an advantage to the one celled organism in a 
cytoplasmic union, even without nuclear fusion. The importance 
of this cytoplasmic union in the cases of true fertilization where 
the male cell consists of little but the nucleus, as in the mosses 
and ferns, may be much reduced. The existence of such cases, 
however, whether primitive or degenerate, is strongly in favor 
of the view that sexual reproduction may have originated in 
fusions of a simpler type than are found in most plants and an- 
