The Chicago University Text-Book. 
355 
Some added unsteadiness comes too from the knowledge that the 
author of the second part of the Chicago Text-book will teach no 
more and that the Botanical Gazette will lack those model “ Notes 
for Students ” on physiological topics which delighted us by their 
frank criticism and brisk judicial evaluation. 
As in those notes so in this book, one sees Barnes as a teacher 
rather than a worker. He feels strongly the duty of selecting for 
his audience and he does his duty with gladness, so that this last 
writing bears a deep impress of his personality. 
Perhaps the most interesting treatment for this notice will be to 
select for comment some of the special personal characteristics 
of the author’s outlook on the physiology of plants. 
After an introductory page which is designed to lead over from 
morphology to physiology we come to two chapters entitled 
respectively “The Material Income of Plants” and “The Material 
Outgo of Plants.” These contain a curious selection of topics, as 
both respiration and assimilation are excluded from them. The in¬ 
take and the output of water are the main topics and one wonders 
whether putting these in the forefront of physiology—to the degrading 
of the more fundamental vital functions—is due to the fact that for 
the first time in an important text-book the subject of ecology takes 
rank on an equal footing with the older divisions of morphology 
and physiology : for the ecological forms of plants are, of course, 
correlated more closely with water-questions than with “ proto¬ 
plasmic ” functions. 
Barnes’ personality comes out at once in his treatment of the 
relation of the plant to water. He emphasizes the enormous 
amount of water present in plant-tissues and says that were this 
only visible everyone would recognize that “a plant may justly be 
spoken of as water, held in form by other substances mingled with 
it.” He admits that this is quite the reverse of the ordinary con¬ 
ception and indeed we have only to turn to the Bonn Text-book, to 
a corresponding point in Noll’s exposition of the water-relations of 
the plant, to read “ Plants, in spite of the great amount of water 
contained in them, are of the nature of solid bodies ” (3rd English 
Ed., p. 173). 
It is a nice question for philosophical discussion to determine 
which is the more important point of view to insist on—the con¬ 
tinuity of water through the whole plant, cell-wall, protoplasm, sap- 
vacuole—or the discontinuity of properties between these three 
parts. While both aspects have very great importance the reviewer 
