1906] SPALDING—ABSORPTION OF WATER BY LEAVES 267 
period gained 5.1 per cent.; Parkinsonia, Prosopis, and Acacia 
gained 0.4 to 1.5 per cent.; iil Zizyphus, Fouquieria, and Koer- 
berlinia, all without leaves, showed almost no appreciable gain. 
Species of Sphaeralcea and Encelia gained in weight 5.4 and 6.2 
per cent. respectively, but promptly lost all they had gained by a 
few minutes drying. 
It will be noticed that of the plants employed in this prelimi- 
nary work those without leaves absorbed no water to speak of, 
while those in leaf fell into two categories, those absorbing and 
those not absorbing water in quantity. The experiment, there- 
fore, pointed to leaves rather than internodes as agents of absorption, 
and indicated, apart from Sphaeralcea, Encelia, and the peculiar 
Atriplex, only the woody species belonging to the first group as 
likely to prove capable of absorbing much water. 
Starting with the suggestions derived from these facts, a more 
careful and detailed study was undertaken. Cut shoots were still 
employed for a time, though it was understood that confirmation 
of results would necessitate the use of entire plants, and these were, 
as a matter of fact, employed to a large extent in the later work. 
Care was exercised in the selection of material, and in each case 
its source and any conditions liable to affect results were noted. 
GROUP I. 
Celtis pallida. 
Four specimens of this species were selected, all in good condi- 
tion, though apparently not as active physiologically as they would 
have been earlier in the year. Numbers 1 and 2 were fresh shoots, 
while numbers 3 and 4 were small branches taken from older bushes. 
Those numbered 1 and 3 were cut so as to include a large leaf sur- 
face as compared with the other two. In every case the cut ends 
were covered at once with vaseline, and the first weighing was made 
as soon as practicable after bringing them to the laboratory. They 
were then wet at frequent intervals for a little more than three hours, 
and; after drying the surface, were weighed again, after which 
they were left in the laboratory to dry until the next day, when the 
same steps were repeated. Finally they were immersed in water 
over night and again weighed. 
