330 Marshall Ward . — On a lily -disease . 
protuberance, x in d , on the lower side of the terminal segment 
of the main hypha, and from the first this branch was directed 
towards the second segment of the branch below. At 12.30 
this was very distinctly seen to be the case, for the protuberance 
in question was curved slightly backwards, so that its apex 
travelled in a line at right angles to the axis of the branch 
below ; but (as shown in e) a second protuberance was by this 
time apparent, springing from the middle segment of the lower 
branch and with its axis in the same line as that along which 
the apex of the first one was travelling. At 12.55 (Fig- 2 7,/ 
and g) these two protuberances were nearly in contact by their 
apices; and by 1.10 p.m., as seen in /z, they had become 
united, and their protoplasm continuous, the double partition 
where the tips came in contact having been dissolved away. 
As will be seen by referring to Figs. 28, 29, and 30, very 
similar phenomena are observed in others of the numerous 
cases of these fusions of small lateral branches (Fig. 30), or of 
larger terminal ones (Fig. 28), and the next step is to see if 
any explanation can be offered of this strange process. 
It seems to me, after observing numerous cases of these 
fusions in this and other fungi, that we must distinguish 
between two steps in the process. In the first place there is 
some cause at work which determines the formation of a 
branch, and then, in the second place, we have to assume that 
some other cause determines the direction in which the branch 
grows, at least in the cases given and in similar ones. If, 
now, we give due consideration to the development of the 
densely branched organs of attachment which have been 
described above, it seems suggestive that copious and rapid 
branching occurs at just those places where the solvent action 
of some substance in the protoplasm is most evident. I may 
anticipate matters so far as to state that it is just at these parts 
that a ferment capable of swelling and dissolving cellulose is 
formed most abundantly, and it is in the highest degree probable 
that the presence of this ferment determines the place of origin 
of the branching. 
I have tried to figure the process to my own mind somewhat 
