2GG MKKISTIC VARIATION. [PART I. 



teeth, the animals shewing the greatest frequency of extra teeth 

 were the domestic Dogs, the Anthropoid Apes and the Phocidae. 



Attention is especially called to the fact that the variability of 

 domestic animals is not markedly in excess of that seen in wild 

 forms. From tlu- hypothesis that Variation is uncontrolled save 

 bv Selection, there has sprung an expectation, now fast growing 

 into an axiom, that wild animals are, as such, less variable than 

 domesticated animals. This expectation is hardly borne out by 

 t In- tads. It is true that, so far as the statistics go, supernumerary 

 teeth were more common in domestic Dogs than in wild Canidae, 

 and though the number of Cats seen was small, the same is true 

 in their case also as compared with wild Felida 1 . But though it is 

 true that the domestic Dog is more variable in its dentition than 

 wild Dogs, it is not true that it is much more variable than some 

 other wild animals, as for instance, the Anthropoid Apes or the 

 genus I'liin-'i. Tin- doctrine that domestication induces or causes 

 Variation is one which will not, I think, be maintained in the 

 light of fuller evidence as to the Variation of wild animals. It 

 has arisen as the outcome of certain theoretical views and has 

 received support from the circumstance that so many of our 

 domesticated animals are variable forms, and that so little heed 

 has been paid to Variation in wild forms. To obtain any just view 

 of the matter the case of variable domestic species should be com- 

 pared \\ith t hat of a species which is variable though wild. The 

 greal variability of the teeth of the large Anthropoids, appearing 

 nt merely in strictly Meristic and numerical Variation, but also 

 in frequent abnormalities of position and arrangement, is striking 

 both when it is compared with the rarity of variations in the teeth 

 of other Old World Monkevs and the com i> rut ire rarity of great 

 variations even in Man. If the Seals or Anthropoids had been 

 domesticated animals it is possible that some persons would have 



n in their variability a consequence of domestication. 

 When the evidence is looked at as a whole it appears that no 

 genera I i/at ion of this kind can lie made. It suggests rather that 

 the variability of a form is, so far as can be seen, as much a part 

 of its specific characters as ;i ny other feature of its organization. 

 Of such frequent Variation in single genera or species some 

 curious instances are to be found among tile facts given. 



Of Canis cancrivorus, a S. American Fox, the majority shewed 

 some abnormality. Of Felis fontanieri, an aberrant Leopard, two 

 skulls only are known, both showing dental abnormalities. In 

 Seals only four cases of reduplication of the first premolar were 

 seen, and of these two were, in Ci/*tj>!i<>r<i rrixt<tt<i. The number 

 of cases of abnormality in the genus Ateles is verv large. Of six 

 specimens of CriMsiirrliiix zcltrn, two shew abnormalities. Of the 

 very few skulls of Myrmecobius seen, two shew an abnormal num- 

 ber of incisors. Three cases of Variation were given in Canis 

 mesomelas, not a very common skull in museums. On the other 



