Jan. 1905.] BOTANICAL SOCIETY OF EDINBURGH. 67 
with rust, Both uredospores and teleutospores were found 
on the wheat plants. 
In all the above places I failed to find any plant, allied to 
the barberry or not, which might play the role of the inter- 
mediate host, A®cidiospores, it is true, may be carried from 
Southern Europe by the prevalent northerly winds, but 
nearly all my observations go to show that the wind after all 
is not so responsible—at least where long distances over sea 
are concerned—for the spread of the disease as it was once 
supposed to be the case, 
For if the spread of the rust on wheat is mainly due to 
eecidiospores brought by the wind, severe cold should not 
tend to reduce the spread and activity of the fungus, And 
yet this is the case—for cold, as we have seen, not only 
checks, but in many instances even tends to exterminate, the 
disease, 
The life-history of this dreaded fungus is undoubtedly 
wrapped up in mystery as yet, and affords a field for further 
investigation and research. Until we succeed in solving the 
question and becoming fully acquainted with the nature, 
mode of attack, and life-history in general of the fungus, we 
cannot possibly hope to find the necessary measures for com- 
bating successfully the disease. 
The PRESIDENT rea‘l a paper on “ Physiological Drought as 
a principle in Gardening.” By means of actual plants and 
of a series of lantern slides, he illustrated the important part 
water plays in plant life and structure, and more particularly 
pointed out that in the treatment of many garden plants the 
question of physiological drought was of the greatest 
importance. 
Mr. Ropert ADAM contributed an interesting series of 
slides of British Plants in Nature, and Dr. BORTHWICK, a 
further series of Fungi in their natural habitat. 
