PUBLICATIONS REVIEWED 137 
boxes, and methods of feeding, and concludes with statements re- 
garding the necessity of suppressing the enemies of birds and the 
necessity for cooperation if a rational protection of the birds is 
to be brought about. We are pleased to note that progress has 
been made both in Germany and in our own country in the di- 
rection of saying from extinction certain species which are not 
able to cope with changed conditions resultant from the coming 
of civilization into these countries. With the author of this lit- 
tle book we hope that the time is not far distant when other 
countries of the world will heartily join in the movement. 1. J. 
Significance of White Markings in Birds of the Order VPasseri- 
formes. By Henry Chester Tracy. University of California Pub- 
lications in Zoology. Vol. 6, No. 18, pp. 285-312. December 28, 
1910. 
This vexed question is discussed by Mr. Tracy, not in the hope 
that he might be able to finally settle it, but rather “for the pur- 
pose of testing the validity of one of the earliest recognized cate- 
gories of coloration, that of “Directive Markings,” in a single or- 
der of birds.” His discussion takes the form of a review of the 
discussion of Thayer, who regards white markings as ‘ Conceal- 
ing,” since the two supposed functions might be regarded as an- 
tagonistic. Under the heading of “Intrinsic Factors in the Hyo- 
lution of Color” he properly questions the presumption of Riddle 
that color patterns, particularly the white patterns, may be due to 
rhythms of blood pressure. Under the topic of “ White Markings 
as Visual Clues,’ much evidence is submitted to prove that white 
markings do often serve as clues, even though they may, under 
certain conditions, also serve the purpose of concealing colora- 
tion. This is true of the birds of the forest as well as birds of 
the open. The paper is a welcome contribution to the study of 
this difficult problem. Te, do 
Photography for Bird-Lovers. <A practical guide. By Bentley 
Beetham, F.Z.S. With photographic plates. London: Witherby 
& Co. 
After some pertinent remarks concerning the comparatively 
greater satisfaction resulting from this method of hunting birds 
as against the hunt with a gun, the author proceeds to give de- 
tailed directions for pursuing this “sport” in ten chapters. The 
author gives unmistakable evidence of being master of his sub- 
ject in all its details. The directions for making pictures of birds, 
