TEETH AND THEIR VARIATIONS. 225 



where there is no need for swiftness of flight, the feet 

 have not undergone this adaptive modification, so that 

 the whole structural alterations have been confined 

 to the teeth. 



In conclusion, we venture to think that sufficient 

 has been said to show what an extremely interesting 

 study is that of teeth. These organs are, indeed, 

 interesting not only from their curious and often 

 beautiful forms, but also, as we have striven to show 

 in the foregoing paragraphs, as affording a concise 

 and, so to speak, epitomised summary of- the degree 

 of evolution which any particular group of animals 

 has undergone in the course of time. 



