50 Permanence and Evolution. 



tology seems to show) our present fauna is only a 

 feeble excerpt of that of the latter tertiary age,* 

 then there is no reason why there may not just as 

 soon have been ten times that number or more. 



Therefore not much need be said in detail. 

 Sheep brought into many tropical countries 

 show a tendency to grow more hair and 

 less wool ; this is well explained by Darwin 

 as being only a case of unequal development 

 (hygienic). There are two breeds said by 

 Darwin to have suddenly originated in modern 

 times, one in France, the other in the United 

 States of America. The one is the Mauchamp 

 (or silky- woolled) sheep, raised by M. Graux 

 at Mauchamp, in France, from a Merino ram- 

 lamb born in 1828. Darwin very truly observes 

 that if nothing were known of the origin of this 

 variety, many naturalists (those of the school 

 followed by the author) would have felt certain 



* See the late Dr. Falconer's " Palaeontological Memoirs," 

 vol. i. p. 245. 



