[Vor. 1 
20 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
as a result of an application of a film of Bordeaux mixture, the 
following questions arise: (1) What is the physical or chemical 
basis of the increased evaporation from plant surfaces covered 
with Bordeaux mixture? (2) Is the increased evaporation in 
any way related to the increased vitality or longevity of sprayed 
leaves? Neither of these questions may be answered intelli- 
gently at present. With respect to the first, we have arranged 
experiments to determine the effects of Bordeaux on the passage 
of water vapor through non-living membranes; but the results 
are thus far conflicting, due possibly to the fact that we have 
not yet used membranes which are satisfactory analogues of 
leaves. Experiments in this direction will be reported later. 
No relation of transpiration to inereased longevity can be 
foretold, although it seems possible that the highest efficiency 
equilibrium relation of longevity may involve, in certain plants, 
a relatively high transpiration rate as either a direct or an 
indirect factor. Хо answer to the question will be satisfactory 
until a further study of other effects (*'stimulation," increased 
*assimilatory activity," etc.) of Bordeaux mixture shall have 
been made. 
BIBLIOGRAPHY 
1. Aderhold, R. Der heutige Stand unserer Kenntnisse über die Wirkung und 
Verwertung der Bordeauxbrühe als Pflanzenschutz-mittel. Jahresb. d. Verein- 
igung der Vertreter der ang. Bot. 1: 12-36. 1904. 
2. Bain, S. M. Тһе action of copper on leaves. Тепп. Agr. Exp. Sta. Bul. 15: 
1-108. 1902. 
3. Bayer, L. Beitrag zur pflanzenphysiologischen Bedeutung des Kupfers in der 
Bordeauxbrühe. Inaug-Dissert., Kónigsberg, 1902 [cf. Schander (18)]. 
4. Clark, J. F. On the toxie properties of some copper compounds with reference 
to Bordeaux mixture. Bot. Gaz. 33:26-48. 1902. 
5. Clinton, G. P. Spraying potatoes in dry seasons. Conn. Agr. Exp. Sta. Report 
1909-10: 729-752. 
6. Crandall, C. S. Bordeaux mixture. Ill. Agr. Exp. Sta. Bul. 135 : 201-296. 
1909. 
7. Duggar, B. M. Peach leaf curl and notes on the shot-hole effect of peaches and 
plums. Cornell Agr. Exp. Sta. Bul. 164: 371-388. 1899. 
8. Ewert, R. Der wechselseitige Einfluss des Lichtes und der Kupferkalkbrühen 
auf den Stoffwechsel der Pflanze. Landw. Jahrb. 34: 233-311. pl. 2-4. 1905. 
9. Frank, A. B., and Krüger, Fr. Ueber den direkten Einfluss der Kupfervitriol- 
kalkbrühe auf die Kartoffelpflanze. Arb. d. deut. landw. Ges. 1894: 1-46. 
10. , Ueber den Reiz welchen die Behandlung mit Kupfer auf die 
Kartoffelpflanze hervorbringt. Ber. d. deut. bot. Ges. 12: 8-11. 1894. 
11. Hawkins, L. A. Some factors influencing the efficiency of Bordeaux mixture. 
Bur. Pl. Ind. О. 5. Dept. Agr. Bul. 265: 1-29. 1912. 
