356 Professor Owen on 



the robust claviculate and unguiculate fore limbs with which 

 they combine their forces in the Herculean labour. 



The Professor then referred to the Mylodon robustus, a 

 smaller extinct species of the same natural family of phyllo- 

 pagus Bruta^ and to the additional arguments derivable from 

 the skeleton of that animal in favour of the essential affinity 

 of the Megatherium to the Sloths ; and the light which the 

 remarkable healed fractures of the skull of a specimen in the 

 Museum of the College of Surgeons threw upon the habits 

 and mode of life of the species. 



Hypothesis of the Degeneration of the Ancient Megatherioids of 

 South America into Modern Sloths, erroneous. 



Finally, with reference to the hypothesis of the German 

 authors and artists of the degeneration of the ancient Mega- 

 therioids of South America into the modern Sloths, the author 

 remarked that the general results of the labours of the anato- 

 mists in the restoration of extinct species, viewed in relation 

 to their existing representatives of the different continents 

 and islands, commonly suggested the idea that the races of 

 animals had deteriorated in point of size. Thus, the pal- 

 mated Megaceros is contrasted with the Fallow Deer, and 

 the great Cave Bear with the actual Brown Bear of Europe. 

 The huge Diprotodon and Nototherium afford a similar con- 

 trast with the Kangaroos of Australia, and the towering 

 Dinornis and Palapteryx with the small Apteryx of New 

 Zealand. But the comparatively diminutive aboriginal 

 animals of South America, Australia and New Zealand, 

 which are the nearest allies of the gigantic extinct species, 

 respectively characteristic of such tracts of dry land, are 

 specifically distinct, and usually by characters so well marked 

 as to require a sub-generic division, and such as no known 

 or conceivable outward influences could have progressively 

 transmuted. Moreover, as in England, for example, our 

 Moles, Water- Voles, Weasels, Foxes and Badgers, are of 

 the same species as those that co-existed with the Mammoth, 

 Tichorrine Rhinoceros, Cave Hyaena, Bear, &c., so likewise 

 the remains of small Sloths and Armadillos are found associ- 

 ated with the Megatherium and Glyptodon in South America ; 

 the fossil remains of ordinary Kangaroos and Wombats 



