Complex Life — The Invertebrates 



sitored in a pouch on the back of the parent until the early 

 stages of growth are completed while in one of the South 

 American toads, the eggs are placed by the male on the 

 back of the female where they sink in cavities of the skin. 

 Here, true to their ancestral heredity, they pass through 

 the tadpole metamorphosis and emerge with the form of 

 the adult in a similar manner to that of the marsupialia. 



It is a noteworthy fact that many of the frogs, like many 

 of the fishes are cannibals and eat their own offspring. The 

 toads live chiefly on insects, and insect larvae while the prin- 

 cipal food of the frogs consists of water insects, small fishes, 

 snails, bugs, and such other small life as live in marshy 

 places. Another noteworthy fact is the power some of this 

 group possess to change their color to correspond to the 

 objects about them as a means of protection against their 

 enemies. 



In some of the tree toads this chameleonic character- 

 istic is so highly developed that they have the power of 

 changing their color with each change of position. Others 

 have gorgeous colors, perhaps, as danger signals, which give 

 warnings to their enemies to beware of the poison which 

 they possess while in others the warty protuberances of their 

 skin emit a milky, bitter secretion that protects them against 

 their enemies. 



The amphibians, the same as the fishes, are cold- 

 blooded; that is they do not possess the power of regulat- 

 ing the body temperature and as a consequence, their move- 

 ments are noticeably reduced when the temperature sur- 

 rounding their bodies is lowered. The heart of the fishes 

 has only two cavities, an auricle and a ventricle. But when 



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