i860.] 



PEDIGREE OF MAMMALIA. 



A i 



wolves, jackals, &c. ; yet these have, on our vieiv, descended 

 from a single remote unknown progenitor. With domestic 

 dogs the question is simply whether the whole amount of 

 difference has been produced since man domesticated a single 

 species ; or whether part of the difference arises in the state 



DIAGRAM I. 

 A 



MAMMALS, 

 NOT TRUE MARSUPIALS NOR TRUE PLACENTALS. 



a 

 or 

 c 



Cr 



& 



Q 



<J 



or 

 ui 

 O 

 >- 



o 



c 



z 



o 



DIAGRAM II. 



PLACENTALS 



3 

 O 



a 

 n 



z 

 -( 

 e/1 



A 



TRUE MAiRSUPIALS 



LOWLY developed: 



TRUE MARSUPIALS 

 HIGHLY DEVELOPED: 



A 



PRESENT. 

 MARSUPIALS 



KANGAROO 

 FAM: 



of nature. Agassiz and Co. think the negro and Caucasian 

 are now distinct species, and it is a mere vain discussion 

 whether, when they were rather less distinct, they would, on 

 this standard of specific value, deserve to be called species. 



