360 Marshall Ward, — On a lily -disease, 
yet positively assert that the Polyactis on Phaseolus is the 
same as that on the marrow, but the differences, if they exist, 
are so slight as to escape detection. 
But although Polyactis vulgaris behaves so far almost 
exactly like the lily-fungus, there are one or two points 
of difference to be noted, of sufficient importance to prevent 
any one from confounding them ; to make myself quite certain 
of this, I made simultaneous sowings of the three forms — that 
on the lily, that on Phaseolus , and that on the vegetable 
marrow— in drops of the same brew of Pasteur’s solution, and 
all treated exactly alike. 
In the first place, the conidia of the lily-fungus are about 
twice as large as those of the Polyactis 1 on beans and marrows ; 
1 It is neither necessary nor useful to give a full list, but the following data are 
of importance in the discussion which follows : — 
Polyactis vulgaris , Fr.,has conidia measuring 10-12 x 7-9 /x, according to Saccardo. 
If we take the measurements of different observers, however, the conidia must 
vary considerably, from 10-16 x 7-10 jx. 
Polyactis cana , Berk., has spores measuring 30-33x15-18 /x, as I learn from 
Mr. Massee, who has kindly examined the specimens in Berkeley’s Herbarium 
at Kew for me. 
Polyactis cinerea , Pers. ( Botrytis cinerea of the continental writers), has conidia 
measuring 8-9 x 6-7 /x , according to Saccardo. 
Polyactis fascicularis , Corda. The conidia measure 12-15 x 6-8 ji. 
Now these are the chief British forms in Cooke’s Handbook (1871, vol. ii. p. 601), 
Polyactis vera being a rare form of which I have no measurements. 
Mr. Massee has been so good as to send me drawings and measurements of the 
following additional- /orms : I have also to thank Mr. G. Murray for measure- 
ments of several species : — • 
Polyactis capitata, Berkeley’s Herb., a white form with conidia measuring 20-25 
x 12-16 fx. 
Polyactis umbellata , DC., a dark rusty-brown form with rounded conidia 
measuring 15-17 
And a very interesting form Botrytis ( Cristatella ) corolligenium , Cke. and Mass., 
found at Kew on decaying Calceolaria- ft owers. The plant is pure white, and 
the type in the Kew Herbarium has ovoid conidia measuring 25 x 15-18 \x. 
It is sufficiently clear from the above that the lily -Botrytis, with conidia 
measuring about 25^ long x 15 /t broad, cannot be confounded with the forms 
P. vulgaris or P. cinerea, or any of the small-spored forms. Nor can I identify it 
with Berkeley’s P. cana , though his P. capitata (conidia 20-25 x 12-16) seems to 
present some not unimportant features of resemblance. This could only be decided 
by comparing fresh specimens and by cultivation. In any case, it seems clear that, 
if there is anything at all in the measurements, we must look for this ‘ species ’ 
among the large-spored forms. 
