1863.] DR. J. E. GRAY ON THE SPECIES OF LEMUROIDS. 



135 



leading to such an opinion. "We have, on the contraiy, seen that 

 even when any hybrid specimen has been artificially produced, 

 there is always a strong inclination for the race so produced to re- 

 turn to the original form. And I must consider, as the authors 

 above quoted have stated, that " the fact that species do in botany 

 (and, I may add, zoology) stand out as the most prominent term in 

 the series between individual and class is perhaps the most salient 

 obstacle to the reception of the doctrine of the origin of these 

 through variation by natural selection," or, I would add, any other 

 theory that has been suggested ; indeed it appears to be an insur- 

 mountable difficulty to the reception of the theory of the gradual 

 modification of species altogether, however much such a theory 

 might, if it were true, explain some of our difficulties*. 



[ 



I'arecia varia. 



3. Varecia- 



The cheek and chin surrounded by a fringe of long hair. The 



* I would refer to Professor Haughton's paper on the ' Origin of Species,' read 

 before the Natural History Society of Dublin, on the 21st November, 1862, as 

 a most excellent corrective of such fallacious theories. 



