840 



TITANOTHERES OF ANCIENT WYOMING, DAKOTA, AND NEBRASKA 



Vries mutations were chieflj^ iu his mind. This 

 raises the inquiry as to tlie normal or abnormal char- 

 acter of major and minor saltations. 



MOST SALTATIONS IN MAMMALS ABNORMAL 



Are saltations natural or artificial products? Are 

 they normal or abnormal? Against the repeatedly 

 observed continuous origin of normal adaptive recti- 

 gradations and allometrons in titanotheres and other 

 quadrupeds still stands the pure Darwinian hypothesis 

 of the fortuitous and discontinuous origin of similar 

 biocharacters as material for natural selection. 



It is true that some characters, such as horns, do 

 arise suddenly. It is therefore interesting to compare 

 20 distinct types or kinds of major and minor salta- 

 tions in 11 different families of mammals — man, 

 horses, cattle, sheep, deer, pigs, dogs, cats, rabbits, 

 guinea pigs, mice, in which saltations that are 

 closely or exactly similar repeatedly occur. Our chief 

 authorities are Allen, Azara, Bateson, Brinkerhoff, 

 Castle, Darwin, Davenport, Haeckel, Percival, Poul- 

 ton, Kidgeway, Koot, Seton, Sutton, Twining. The 

 accompanying table presents the very impressive 

 results obtained by this comparison. 



Comparison of twenty saltations in eleven Tcinds of mammals 



Teratology and Mendelism have alike revealed the 

 fact that most saltations represent failures or abnor- 

 malities in the germinal mechanism. Some occur 

 under natural conditions, but most of them under arti- 

 ficial conditions of environment. Many of these 

 saltations are dominant characters in heredity, and 

 in some domestic breeds, through either artificial 

 selection or failure of artificial selection, they become 

 fairly numerous. We have tailless cats, solid-footed 

 (syndactyl) pigs, polydactyl cats, curly-haired horses, 

 short-legged sheep (ancon), and hornless cattle of 

 several breeds (Angus, niata). It is possible also 

 that races of . wild animals have been established 



through germinal saltations, such as the four-horned 

 antelope of India {Tetracerus) , which is comparable 

 to the four-horned domestic breed of sheep. 



Paleontologic and anatomical research on the 

 mammals for over a century has failed to demonstrate 

 in a state of nature a single example of the sudden 

 origin of such important characters as the horns. 

 There is reason to believe that if peculiar or anomalous 

 mammals do arise under natural conditions they are 

 driven away from the herds and not allowed to breed. 

 Thus it may be said that in neither zoology nor 

 paleontology has any evidence been adduced thus far 

 of the saltatory origin of allometrons or rectigrada- 

 tions under natural conditions. 



