50 FREE AND FIXED ANIMALS 



that the latter ever really takes place is a matter 

 which requires confirmation. 



Other reptiles which take refuge in trees, e.g., 

 Calotes and Varanus, when alarmed, will project 

 themselves from a great height to the ground 

 without elaborating a mechanism for aerial flight. 

 The case of Draco, the flying lizard of Malaya, 

 where such a mechanism is developed (dermal 

 membrane supported by ribs), belongs to a 

 different category ; and the facts seem to show 

 clearly that it is not merely the habit of taking 

 flying leaps, like monkeys, for example, that has 

 led to the formation of organs of flight. 



We may now submit the conclusion that just 

 as all divisions of the animal kingdom display 

 a cryptozoic bias, so do they all show a statozoic 

 tendency. The sedentary habit is referable to 

 a stereotropic basis, and pelagic or pleotropic 

 forms belonging to groups which are pre- 

 dominantly sedentary, have had a probable 

 statozoic origin. All land animals have had 

 aquatic ancestors, or, more precisely, all air- 

 breathers have descended from water-breathers 

 as defined above. The latter are primarily 

 aquatic, and are either stereotropic at the present 

 time, or it may be argued that they have had 

 a more or less remote stereotropic ancestry. 



Thus the permanent fixation of so many 

 aquatic animals is not such a bizarre phenomenon 

 as it appeared to be to the older naturalists 



