Lewis . — The Life History of Griffith si a Bornetiona. 659 
(Fig. 81 ). The actual passage of the fusion nucleus into the auxiliary cell 
was not observed. In no case has a fusion nucleus been seen in any of the 
cells of the carpogenic branch other than the carpogonium, and it seems 
unlikely that it passes into any of these other cells. The position of the 
carpogonium in contact with the auxiliary cell renders it possible that the 
two become connected by resorption of the walls at the point of contact, 
and that the fusion nucleus passes directly into the auxiliary cell, as was 
suggested by Schmitz for other species of Griffithsia , and has been 
demonstrated in Thuretella and Chylocladia by Hassencamp (40). In 
Polysiphonia violacea the communication between the carpogonium and the 
auxiliary cell is transient (Yamanouchi, 93), so that it might well be 
difficult to demonstrate in such a form as Griffithsia. 
The cells of the carpogenic branch after fertilization and the passage of 
the fusion nucleus into the auxiliary cell usually degenerate simultaneously, 
and often the whole carpogenic branch breaks away from its attachment to 
the auxiliary cell, and lies free among the cells of the procarp (Fig. 83). 
In one case the lower cells of the carpogenic branch were seen to have 
withered before the passage of the fusion into the auxiliary cell, which 
lends support to the view that the fusion nucleus passes directly into the 
auxiliary cell and not through the cells below the carpogonium. Miss 
Smith’s account (73, p. 41 ) of the withering of the carpogenic branch was 
not corroborated in the present study. She states that the carpogonium 
first becomes disorganized, ‘ the adjacent cell at the same time apparently 
increases in size, but it also soon loses its contents, and in some cases 
appears to become disorganized, while the two lower cells take a deeper 
stain than before As stated above, the carpogenic branch usually withers 
as a whole, and not cell by cell. 
At the time of the passage of the fusion nucleus into the auxiliary cell 
there is in the centre of the latter a very large clear nucleus. This is one 
of the nuclei originally present in the auxiliary cell. Besides this, two or 
three small nuclei are frequently seen in the peripheral portion of the cell 
(Fig. 81 ) ; these are the remaining nuclei present at the time of the organiza- 
tion of the auxiliary cell. They seem to disappear during the course of 
the further development of the auxiliary cell. 
The fusion nucleus in the auxiliary cell is of very characteristic 
appearance. It differs from the usual type of nucleus in possessing two 
chromatin-nucleoli instead of one. It would seem as if the chromatin from 
the male and the female parent does not fuse completely, and that the 
nucleoli of different origin remain distinct for some time after nuclear fusion. 
The behaviour of the chromosomes in the early divisions of the fusion 
nucleus was not observed, though it would be of considerable interest 
to know whether two distinct groups of chromosomes are formed at this 
stage. 
