338 Marshall Ward. — On a lily -disease. 
enlarge and become distinctly granular, at the same time 
gradually acquiring a yellowish or slightly brownish hue 
(Figs. 43-45). I had occasionally seen a similar exudation of 
drops in previous cultures of fungi, and found among my draw- 
ings of cultures made in Ceylon in 1880 several similar cases ; 
so far, however, I had not been able to establish any satisfactory 
explanation of the phenomenon, though the idea arose that the 
drops might be due to some substance manufactured in the 
cell in larger quantity than could be retained. Before offering 
a more definite explanation, I will describe the drops and their 
exudation in detail. 
If the slightly swollen ends of vigorous hyphae of a well 
nourished mycelium be watched, it will be seen that sooner 
or later some of them become very full of particularly brilliant 
protoplasm (Fig. 45, 1) ; if such a hypha comes in contact 
with a solid body, such as the cover-slip, it simply begins to 
cling to it, and branches to form an organ of attachment as 
described on p. 327. If it remains free, however, it gradually 
begins to exude a small translucent or nearly transparent 
viscid drop (Fig. 45, 2) from the tip, the protoplasm in the 
hypha becoming most beautifully vacuolated meanwhile. 
During the next few hours the exudation continues, and the 
vacuolation increases (Fig. 45, 3 and 4), and the drop slowly 
changes character as described — it becomes granular, and 
acquires a pale brownish-yellow hue. In some cases the 
segment of hypha becomes nearly emptied and collapses, 
and I at one time suspected that the whole matter was 
merely a case of over-turgidity due to the absorption of 
water in quantity too great for the elasticity of the cell- 
walls. But it soon became evident that even if this were the 
case, there must be some cause at work determining the 
absorption of water at just that period in development. 
But when one reflects that these drops are extruded from 
vigorous hyphae developed in Pasteur’s solution, or in the 
juices of fruits, etc., which can by no means be regarded as 
calculated to cause vacuolation by physical action, but, on the 
contrary, would act physically rather as plasmolysing agents, 
