[Vor. 1 
6 ANNALS OF- THE MISSOURI BOTANICAL GARDEN 
quantitative experiments as a result of which they conclude, 
contrary to Rumm, that transpiration is accelerated by spray- 
ing. They state that sprayed leaves are in general more robust, 
thicker and stiffer. They also report an increased yield in 
pot experiments from spraying. АП these indications, as well 
as those of Leydheker (13) and others (1, 12) denote differences 
of yield which are so slight as to be of no fundamental impor- 
tance in the present consideration. Nevertheless, the trans- 
piration data of Frank and Krüger, as already observed, were 
obtained by satisfactory methods, and these are of greater 
interest when taken in conjunction with those of Zucker (22) 
who confirms their results entirely. 
Schander (18) in an extensive paper reports a comparatively 
small amount of experimental work on transpiration, but in 
the cases given his results indicate a retardation of water loss 
after spraying. His experiments with cobalt paper were incon- 
sistent, and twigs of Taxus baccata and potted bean plants 
were then employed, yielding the positive results noted. How- 
ever, his work embraced very few plants, and the transpiration 
differences observed are inconsiderable. He suggests that 
lessened transpiration of sprayed plants is to be expected, 
since the Bordeaux mixture must exert a shading influence as 
a result of the exclusion from the leaf of certain injurious 
rays. He attempts to verify this assumption of partial shad- 
ing by a study of leaf temperatures, but the experiments in this 
direction give no positive evidence for his theory. No adequate 
mention is made of the conditions surrounding these experiments, 
nor of the precautions observed. 
Ewert’s (8) experiments tend to substantiate the views of 
Rumm and Schander; but, unfortunately, the results are 
not satisfactory for accurate quantitative purposes, since 
evaporation from the pots was merely checked and not pre- 
vented,batting being employed to cover the soil surfaces. His 
experiments are of particular interest, however, with respect 
to his graph for comparative respiration in sprayed and un- 
sprayed plants. In the sprayed plants, respiration was found 
to be distinctly lower than in the unsprayed. It will be noted, 
however, that this diminished respiration is scarcely in keeping 
