COLOR ADAPTATIONS. 
275 
A very interesting case of color adaptation for 
the advantage of the individual is that of the small 
lizard found in the desert parts of Central Asia. 
The lizard is sand-colored and has at each angle of 
the mouth a fold of red skin; when the mouth is 
open it bears a remarkable resemblance to a small 
desert flower, and is thus the means of attracting in¬ 
sects to their doom. Might not, perhaps, the beauti¬ 
fully colored patches about the neck and throat of 
some birds have a similar purpose ? 
It must be admitted that there are many instances 
of color for which no explanation suggests itself. 
Probably color has no signiflcance in such cases. 
One color would serve as well as another, and so the 
color which may once have been useful has been re¬ 
tained by the species. Adaptation only takes place 
in qualities that are useful to the race. 
Examples of natural selection in which the facts 
are apparent are quite as numerous as those of arti¬ 
ficial selection. Mr. Darwin and Mr. Wallace, inde¬ 
pendently of each other, collected a multitude of 
facts with care and persistence that border on the 
marvelous. To-day these facts stand unchallenged, 
and have been used as a basis for various conclusions 
for which neither of these scientists would feel him¬ 
self responsible. Every one may observe some of 
these facts for himself. When he does he will be 
unable to deny that food, exercise, and climate have 
a determining influence on both animal and plant 
forms and habits. 
Only a few examples of variation are given under 
