Proceedings 81 
with each set of conditions; but though each species follows 
its own line of growth, the generic or specific resemblance 
remains strong and unmistakable. 
We are now ina position to examinemmore closely the effects 
of Botrytis on the lily. Professor Marshall Ward made a 
prolonged study of this fungus on Li/ium candidum, many 
years ago, and I quote largely from his paper. He had 
observed small, discoloured, orange-brown or buff spots on 
the stems, pedicels, leaves and buds of the white lily, which 
appeared in great abundance in spring. The lower leaves, 
which were attacked first, shrivelled and died, leaf after leaf 
of the flowering shoots followed and the buds were finally 
attacked. If the attack were early enough, the whole head 
rotted off; if the disease did not reach the bud before it 
opened, the flowers were formed, but they were all rather 
spotted and poor-looking. 
Closer examination of the diseased patches showed the 
Botrytis mould on the surface, while the diseased tissues 
were permeated through and through by a vigorous my- 
celium from which rose the conidiophores. Conidia were 
produced on the heads in countless numbers and were 
carried to other plants by every puff of wind or by wander- 
ing insects to which they adhered. The conidium alighted 
on the epidermis of the host plants, and if sufficient moist- 
ure were present, it germinated, pushing out a small tube. 
The tip of the tube excretes a ferment capable of dissolving 
the cell-wall which it then penetrates. Feeding on the 
dissolved and swollen cellulose of the wall, the hyphe 
grow and branch more and more,and excrete larger quan- 
tities of ferment. The cells lose water, the protoplasm 
turns brown and dies, and the fungus flourishes as the 
plant decays. 
A point of peculiar interest in connection with these 
Botrytis moulds is that they are really saprophytes, that is 
they live on dead organic substances. From being sapro- 
phytes some of them have passed over into semi-parasitism 
and prey on living plants, as for example the lily Botryzzs, 
but they have never entirely acquired the parasitic habit ; 
the hyphz secretes a poison which kills the cells and the 
