298 CAUSES OF DEGENERATIVE EVOLUTION 



In the same way may be explained the persist- 

 ence of accessory rudiments of enamel organs in 

 ; the development of teeth. Besides the rudiments 

 of the enamel organs for the milk teeth and 

 permanent teeth, there are additional organs 

 present in a very variable condition and number, 

 nearer the external surface. They are, however, 

 very generally present, and are exceedingly similar 

 to the youngest stages of the normal enamel organs. 

 Kollmann and Gegenbaur believe that they are 

 abortive rudiments surviving from an ancestral 

 condition in which teeth were more numerous. 



CHAPTEE IT 



THE SURVIVAL OF INSTITUTIONS 



WE have seen' that an institution which ceases to 

 be functional without dissolution either voluntary 

 or enforced ensuing, tends to atrophy and dis- 

 appear, while its resources are appropriated by 

 other institutions. It now remains to account for 

 the fact that this atrophy does not generally end in 

 total disappearance. The two following hypotheses 

 may be made : 



1. The structure of a non-functional institution 



may remain intact. 



2. The institution may survive, but in a rudi- 



mentary condition. 



