20 Nebraska Agricultural Exp. Station, Research Bui. 6. 
the exchange of gases by diffusion which continually takes place 
with the exterior. 
For practical purposes these two sources of water loss by 
evaporation (cuticular and stomatal) from the plant may be 
placed in one group, and for the sake of brevity and distinctive- 
ness will be included in this bulletin under the old term "transpira- 
tion/' altho there has been some contention in recent years that 
it should be called merely "evaporation from the plant." 
CHARACTER OF PAST WORK. 
Woodward (1699) 1 was apparently the first to measure this 
water loss. Stephen Hales conducted transpiration experiments 
as early as 1736, having in view a possible application to agri- 
culture. Since then many experiments have been made both for 
purely scientific and for applied purposes. 2 Burgerstein had 
recorded 394 publications on transpiration in 1904, and the 
1 The year in parentheses following an author's name in the text serves 
to associate the reference with a particular publication in the bibliography 
(pp. 209), where the complete title is given. 
2 A number of investigators have reviewed more or less critically earlier 
work on the subject of transpiration. 
(1) Abbe (1905) reviewed a number of experiments and speculated con- 
cerning their practical application. 
(2) Burgerstein (1887, 1889, 1901, and 1904) assembled and discussed 
briefly all available publications concerning transpiration. In 1887, he reviewed 
chronologically 236 publications. In 1887 the general subject of transpiration 
was divided into subtopics, under which the work of investigators to date 
was discussed somewhat critically. Eight additional investigators were listed. 
In 1901, 109 additional publications were listed chronologically, and discussed 
according to general subtopics. The monograph published in 1904 contains a 
list of practically all transpiration studies prior to that date. Methods of 
investigation are reviewed in a critical attitude. 
(3) Briggs and Shantz (1913 b). This publication reviews in a critical 
manner practically all the experiments in which rooted potted plants were 
grown beyond the seedling stage, relative to the use of water by plants in the 
production of dry matter. Experiments with seedlings were not considered 
because of the unreliability of the method. Both a summary of the results 
and a fairly complete statement of the methods used are given with each 
review. 
(4) Montgomery (1912). Various methods of studying the water require- 
ments of plants are outlined, and attention is called to the need for more uni- 
form and accurate methods, so that the work of different investigators may be 
comparable. 
(5) Eberdt (1889). This publication reviews experiments dealing with the 
relation of transpiration to certain atmospheric conditions, including light, 
humidity, temperature, wind, and the effect of jarring. 
(6) Many of the investigators cited in the bibliography on pages 209 to 214 
give partial reviews of previous experiments, and include more or less extensive 
bibliographies. Many investigators not referred to in this bulletin have also 
published excellent bibliographies. 
