William Brown. 
109 
from Convolvulus and do not merely visit it for shelter. On the 
other hand, the harebell, Campanula rotundifolia L„ seems to be 
visited merely for shelter, as we have seen Syrphids in this flower 
only in the evening or during showers. 
We hope to continue our observations on the visits of 
Diptera during the present year, as it would appear that there 
is much to be done in this rather neglected branch of ecology. 
ON THE PHYSIOLOGY OF PARASITISM. 
By William Brown, M.A., D.Sc. 
(Department of Plant Physiology and Pathology , Imperial College 
of Science and Technology). 
N investigation, begun at the suggestion of Professor V. H. 
-L*- Blackman and carried out under his general supervision, has 
been in progress for some years, having as its object a study of the 
physiological phenomena associated with fungal parasitism. 1 With 
the progress of the research, new branches have been opened, in 
many cases so inter-related that a definite pronouncement on any 
one cannot be given till others have been sufficiently explored. 
Thus publication has not kept pace with the actual progress of the 
investigation. Many results have been obtained, some which are 
so well established that they will shortly be published in final form ; 
others which, though in themselves sufficiently established, cannot 
be dealt with fully until their exact relationships with other 
1 The following papers embodying certain results have been published from 
time to time in the “ Annals of Botany” under the general title of “ Studies 
in the Physiology of Parasitism.” 
I. W. Brown; “The Action of Botrytis cinerea.” Ann. Bot., Vol. XXIX, 
1915, p. 313. 
II. V. H. Blackman and E. J. Welsford ; “ Infection by Botrytis cinerea." 
Ann. Bot., Vol. XXX, 1916, p. 389. 
III. W. Brown; “On the Relation between the Infection Drop and the 
underlying Host Tissue.” Ann. Bot., Vol. XXX, 1916, p. 399. 
IV. W. Brown ; “ On the Distribution of Cytase in Cultures of Botrytis 
cinerea." (In the press) Ann. Bot., Vol. XXXI, 1917. 
