LECTURE VII. 305 



and appropriate excitability ; and it seems 

 further necessary that such appropriate pe- 

 cuharities should be restricted to the indi- 

 viduals which belong to certain species 

 or genera of vegetables and animals. If 

 such properties were not thus limited, but 

 general, hybrid productions might become 

 common ; and as the offspring resembles 

 its parents, great diversities of vegetables 

 and animals would be produced, so as even- 

 tually to destroy all the original and strik- 

 ing distinctions of form and character which 

 Nature has instituted. Nature has also 

 made mules in general unprolific, as if she 

 had said, " Thus far may you go, but no 

 farther." I know that some exceptions to 

 this rule are occasionally to be met with, 

 but to these the grammatical adage seems 

 particularly appropriate, " Exceptio jjrobat 

 Regulamy 



The offspring may more particularly re- 

 semble the male or the female parent, or 

 equally resemble both, as is evident in the 

 common mule. Now, thinking as Mr. 

 Hunter did about the formation of the em- 



X 



