Marshall Ward . — On a lily -disease. 329 
The next feature of interest in the mycelium is the cross- 
connections of the hyphae, a phenomenon of constant occurrence 
in cultures of three or four days old and upwards. As seen in 
Fig. 17 these cross-connections may be very numerous, and 
may occur, so far as I can make out, between hyphae of all 
orders. The least interesting case is when two hyphae lying 
nearly parallel and close together simply become joined by 
cross-branches, as in Fig. 19; but in the same figure I would 
draw attention to the remarkable case shown at x, where a 
branch, short and thick, coming down from the upper hypha, 
is met by two small and much thinner ones from the lower 
one. These two small thin branches have obviously bent over 
towards a common point, the extreme tip, of the larger 
branch, and then fused with it. But two other little branches 
have also been developed from the lower hypha, and their ends 
are also curving over towards the same point , as if to fuse with 
the large hypha. 
It was such cases as this, and some still more remarkable 
ones which I had observed in another fungus growing on 
potatoes, which led me to place cultures under continuous ob- 
servation, so that I could follow this process of conjugation of 
the hyphae. It is not necessary to describe in detail the pre- 
cautions and preparations necessary for this : active cultures 
in hanging drops are placed beneath microscopes, certain 
branches are fixed in the field of view, and records made from 
time to time. It is simply a matter of patient observation, 
aided by a little experience in choosing hyphae likely to emit 
the conjugating branches before night. 
In Fig. 27 is a case which came under notice so to speak 
accidentally, because I was at the time following the develop- 
ment of the organs of attachment, and was watching the tip of 
the hypha to that end. 
The hypha a was drawn at 7 p.m. on July 18th. At 6.30 
a.m. on the 19th it had grown slowly (the temperature being 
low) to the extent shown in b ; c represents the state of affairs 
at 10 a.m. on the same day. At 11.40 a.m. on the same day 
(July 19th) a branch was beginning to develop as a minute 
z 
