86 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



Number of brown lizards 



Total Total 

 B B B B G & B 



+ + + 

 Green foliage 8 



Dark green foliage 1 1 2 4 



Concrete 1 2 3 6 



Brown tree trunk 1 1 3 



Fence rail 1 3 7 11 22 



Totals 3 7 7 17 43 



Except the lizards seen on green foliage, the ntunber of green 

 animals equals the brown ones. No brown ones were noted on 

 green foliage but the observations here recorded are by far too 

 limited to permit definite conclusions to be drawn. There was 

 some difficulty in deciding whether an animal resting on a brown 

 fence rail amid a mass of green foliage should be classed as one 

 resting on a fence rail or on green foliage, but it was decided to 

 place these with the former. 



One is justified, however, in drawing one conclusion from the 

 table, namely, that under approximately the same conditions of 

 temperature and light both green and brown lizards may be found 

 and, even on sunshiny days with a moderate temperatiu-e, the 

 green ones may even outnumber the brown ones. According to 

 Parker, brown should be the prevailing color. It does not appear 

 that in their natural environment the reason for the greater num- 

 ber of green lizards can be accounted for on the ground that these 

 animals reacted more strongly to temperature than to light. 



According to Parker and Starratt, the Anolis remains brown 

 at io°C. and remains green at 4o°C., regardless of light. One 

 would expect then, that at a temperature of 2 5.5°C., if there were 

 a greater susceptibility to temperattire, the brown state would 

 prevail for at this temperature there is active both the light and 

 medium temperature influence. 



Evidently a factor which is of extreme importance in influencing 

 the color state is the emotional or nervous condition which can not 

 be easily controlled. The effect of the organs of internal secretion 

 which are under the control, directly or indirectly, of the nervous 

 system probably also influences the color states. 



Ditmars states that the sleeping Anolis is invariably green and 

 that the same color is present during anger or fear. He states 

 that if a cage containing a nimiber of these lizards be shaken, all 



