RELATIONSHIP OF SPECIES. 35 



kinship concerning such an important matter as the production 

 of young (and incidentally the continuation of the race, even if 

 only a mongrel one), one has only to summarise the instances 

 given above, such as : — 



The non-production of any young between members of the 

 same species (Oryctolagus* cuniculus and 0. huxleyi). 



Between members of the same genus (Bos taurus and 

 B. bubalus). 



The production of sterile hybrids between those of another 

 genus, Equus (E. caballus and E. asinus). 



And the opposite results, such as the production of hybrids 

 between members of even different families (Ligurinus and 

 Acanthis). 



And the production of possibly fertile hybrids between 

 different genera, as Cercopithecus and Cercocebus, Macacus and 

 Cynopithecus, and Macacus and Papio. 



With a possible exception of Cercopithecus, I should imagine 

 all the hybrids of the Cercopithecincs would be fertile ; a suppo- 

 sition hardly likely to be proved either way, unless, indeed, the 

 subject receives as much attention in the future as it has neglect 

 in the past. 



(To be continued.) 

 * More generally known as Lepus. 



