452 Hartog . — The Alleged Fertilization 
without any trace of a cell-wall, on its free course to the 
oospore ; this is inexplicable. Now Professor Trow has 
already told us : J In the preparations which I have made and 
used for further study, I have never seen a loose or misplaced 
section, and have never been at a loss to locate any section 
of a series. It is fortunate that it is possible to attain certainty 
in this direction, for there can be no doubt that the oogonia 
and oospores are too thick and dense for clear pictures of 
their contents to be obtainable by any other method than 
one which involves sectioning ’ (p. 151). But he has omitted 
to figure the upper and lower sections of the very set to which 
this solitary case of penetration belongs; he has not noted or 
explained the absence of the cell-wall from the free part 
of the fertilizing tube, and the absence of the beautiful 
cytoplasmic network which is so obvious even in the 
specimens prepared in toto , and which ex hypothesi should 
be so much more clearly seen in sections. For the present, 
then, it is at least permissible to regard the preparation as 
unsatisfactory, and to explain the case as one in which the 
fertilizing tube has passed over the surface of the oospore 
without penetrating it. Indeed, Professor T row’s observations 
on the living specimen confirm those of the supporters of the 
apogamy of Achlya : £ Neither in this case nor in that of many 
others examined, have I been able to trace the entry of the 
fertilization-tube into the egg ; it seems to grow past it, and 
on the side furthest removed from observation, possibly 
influenced thereto by the illumination from below 5 (p. 142). 
Thus, like the rest of us, he has found that the fertilizing tube 
passes on, leaving no trace of its futile attempts to perform 
the ancestral functions. He assumes, however, that a gameto- 
nucleus is transmitted to the oospore by the unseen, tem- 
porary penetration of the oosphere ; and gives no hint as to 
what becomes of the part of the tube that he wishes us 
to believe has penetrated into the egg. There is no trace 
of it on the wall of the oospore at any time, even in his own 
sections. The tube bears no branch, reveals no scar ; one 
can therefore only infer that it must be withdrawn after it has 
