1914) 
DUGGAR AND COOLEY—FILMS AND TRANSPIRATION 5 
vines or give increased yield, while spraying with Bordeaux 
mixture did." 
Although this theoretical explanation did not come to our 
attention until the experimental work reported in this paper 
was complete, it was, in modified form, the only possible opinion 
which we felt inclined to advocate, as а clue to the increased 
longevity caused by Bordeaux, until the contrary evidence 
yielded by our experiments. 
Review ОҒ LITERATURE 
Тһе experimental work undertaken in the past to determine 
the nature of the Bordeaux influence (apart from direct injury) 
has touched mainly upon (1) questions of increased photo- 
synthesis due either to ‘‘stimulation” of chloroplastid or 
chlorophyll development, or to a direct influence upon light 
quality; (2) changes in the respiratory rate, or surmised effects 
upon metabolism; and (3) a modification of the normal rate of 
transpiration. A few observations from the extensive liter- 
ature with particular reference to its bearing on transpiration 
may be cited. 
Rumm (16) finds that in sprayed grapes the chlorophyll 
content of the leaves increases and the fruit ripens earlier with 
a higher sugar percentage. Не attributed these phenomena 
to the higher *assimilatory activity," and in turn relates this 
to the following observation on transpiration:—that abscised, 
sprayed twigs remain fresh longer than those unsprayed, from 
which it is deduced that there is a falling off in transpiration 
as a result of spraying. Through independent observations 
made during the same year, Müller-Thurgau (15) and Bayer 
(3) subscribe to the view that lessened transpiration follows 
spraying. Moreover, this confirmation of Rumm is obtained 
by the former through an experiment which also proclaims 
that the reduction in transpiration as а result of spraying 
may be as much as forty per cent. Nevertheless, the report 
referred to is extremely brief and does not indicate clearly the 
condition of the plants during the period of observation, a 
matter most important in the final interpretation of the data 
afforded. 
Frank and Krüger (9, 10) reported some rather extensive 
