42 2 



GENERAL BIOLOGY 



CONCLUDING WORK. 



As a conclusion to the foregoing studies, make a tabular 

 statement of the adaptive structures observed (a few are 

 stated, as examples) after the following plan: 



Special adaptations of diving beetles. 



Best de 



veloped 



in 



Of head 

 and body 



Character 



^x .-Flattening 

 down of the 

 eyes 



Telescoping 

 of head by 

 prothorax, 

 etc. 



Of appen- 

 dages 



Of vesti- 

 ture 



Upward 

 bending of 

 hind legs, etc. 



( Loss of sen- 



Cybister 



Acilius 



Of what 

 advantage 



Dimished 

 resistance 

 to water 



Better 



rowing 



position 



Involving 



what 

 limitations 



Dimished 



range of 



vision 



Poorer 

 walking 

 position 



< sory antennal 

 (^ hairs, etc. 



The record of this and the consummation of several 

 preceding studies will appear in the last table. 



J. Animal coloration. 



We come now to the examination of characters that are 

 more superficial, more variable, more plastic, and that 

 ordinarily show the most remarkable fitness to environ- 

 ment. We pass by all that internal coloration, however 

 brilliant, that can have no relation to the external w^orld, 

 because hidden from view; such as the red of blood, the yel- 

 low of fat, the iridescent tints of the swam-bladder of fishes, 



