304 BOTANICAL GAZETTE [APRIL 
of chromosomes (ceteris paribus) regulates the size of the nucleus and fur- 
nishes the best evidence for the individuality hypothesis. Nuclear fusion and 
reduction of chromosomes are regarded as important autoregulative processes 
which take place only under definite internal and external conditions. Although 
admitting that the nucleus is of great importance in transmitting hereditary 
characters, he does not believe that it is the sole bearer of such characters, 
but that this function is performed by the nucleus and cytoplasm together. 
It is fortunate that physiological methods are being brought to bear upon 
morphological and cytological problems. The morphologist, with his limited 
knowledge of physiology, is necessarily one-sided in his methods and conclu- 
sions; the physiologist, with a correspondingly limited knowledge of structures 
and development, brings other methods and other viewpoints to the solution 
of the problem; and thus each corrects and stimulates the other, so that 
problems which either could not solve alone become possible. The strict 
morphologist and cytologist will find in this book much with which he cannot 
agree, but nevertheless he will be compelled to recognize it as a valuable con- 
tribution to the subject —CHarLEs J. CHAMBERLAIN. 
Response to light 
Mas? has written a thoroughly interesting book on the response of a 
isms to light. It consists of four parts: “Introduction and historical review 
(pp. 1-57); ‘“‘Experimental observations and discussions bearing on the 
question as to how organisms (especially those without eyes) bend of 08% 
and move toward or from a source of stimulation” (pp. 59-235); “General 
considerations of reactions to light”? (pp. 236-298); and “Reaction in light 
of different wave-lengths or colors” (pp. 304-393). A. bibliograp hy Obes 
pages cites the more important literature on the subject, and frequent and 
excellent summaries make the main conclusions readily accessible. 
The work brings together our knowledge of the response to light in plants, 
motile and sessile, and in animals, protozoa and metazoa. Itisa consideraHo® 
of response to light from the evolutionary point of view. MAsT says; the 
generality of the treatment of the subject of actions in organisms, including 
plants as well as animals, it is hoped will make the work of value to all students 
of nature, especially to those interested in comparative psychology, s00EP 
botany, and physiology.” 
arch. 
plant 
of intensity on different flanks. He uses the maize seedling with see 
that apparently answers all the objections to former methods. His res 
Mast, S. O., Light and the behavior of organisms. 8vo. pp. Xit410 figs. 35° 
New York and London: John Wiley and Sons. rorr. 
