108 HABIT AND INTELLIGENCE, [cHAP. 



and becomes static, in the act of unorganized material 

 acquiring organization.^ 

 Energy of Vital processes go on with the greatest energy where 

 peuds^'on Oxidation is most rapid. This is partly, no doubt, because 

 the supply oxidation yields the necessary supply of heat and other 

 forms of energy : partly also, because the waste, or what 

 may be called the wearing out, of the tissues of the 

 organism goes on most rapidly where vital processes are 

 most energetic : and this will soon be checked if there is 

 not a supply of oxygen to transform the organic com- 

 pounds into freely soluble compounds, which can be easily 

 The most removed from the system. It is, no doubt, in consequence 

 highly or- q£ tjjgge ^^yQ causes that air-breathins animals and air- 



ganized _ o 



plants and breathing plants are in general, and on the average, of 

 are'afr-^ much higher organization than water-breathing ones, and 

 breathers, that air-breathing animals have a more active and energetic 

 life, for air contains a much more abundant supply of 

 free oxygen than water. Warm-blooded animals, which 

 stand at the head of the whole animal kingdom, are with- 

 out exception air-breathers : and, among vegetables, most 

 of the water-breathing kinds are flowerless, and, as such, 

 inferior to the flowering ones in organization. It is no 

 exception to this, but rather a confirmation of it, that 

 many flowering plants, such as the water-lilies, though 

 rooted under water, raise their flowers and part of their 

 leaves into the air, in order no doubt to enable them to 

 Larva and obtain the oxygen they need. It belongs to this class of 

 fonn.*^ facts that there are many instances, among both insects 

 and batrachians (frogs, newts, and similar animals), in 

 which the larva is a water-breather and the perfect form 

 an air-breather ; but not a single instance, I believe, of the 

 converse : for the perfect form in those two classes is 

 always more highly organized than the larva. It is 

 indeed the general law of animal metamorphosis, though 

 subject to some remarkable exceptions, that the mature 

 form is more highly organized than the larva. 



* See chap. i. of Carpenter's Human Physiology. 



