152 'Journal of Comparative Neurology and Psychology. 



so in adults. Young specimens lack the fierceness and sullenness 

 of adults, being capable of domestication. They will feed from 

 the hand and seem to enjoy being scratched under the jaws. 



Summary. — Chelydra possesses a very "ugly" disposition. 

 It is vicious and intractable, displaying a blind impotent rage when 

 brought to bay. In temperament it is extremely slow and sluggish, 

 preferring to lie in wait for its prey rather than actively to search 

 for it. Sometimes, however, it summons sufficient energy to 

 stalk the prey. 



GENERAL SUMMARY. 



It will be noted that certain traits and habits are common to all 

 of the species studied and, since the principal groups of tortoises 

 are represented, these may well be considered as chelonian 

 characters. Certain traits stand out more prominently than 

 others and these should be emphasized. 



1. The love of warmth and repose seems to be one of the few 

 dominant factors in tortoise life. In some cases they seek warmth 

 to their injury. On the other hand, lack of heat is more apt to 

 cause death than any other factor. 



2. Extreme wariness when basking is noticeable in all species 

 that habitually bask. 



3. There is a marked variation in the degree of fierceness or 

 timidity exhibited by different species. These characters seem 

 to run parallel with an aquatic or a terrestrial habitat, aquatic 

 species being fiercer than those with a tendency toward a terres- 

 trial life. 



4. Naturally enough, it is possible to domesticate the less fierce 

 and less sullen species, while captivity inhibits normal activities 

 in the fiercer and more sullen species. 



No general summary of vegetative or reproductive activities 

 is necessary here. The writer, conscious of the incompleteness 

 of his data concerning certain activities, intended to devote 

 another season to the work, but as it seems advisable to publish 

 the facts now as they stand, he hopes to supplement and interpret 

 them on another occasion. 



