THE DARWINIAN THEORY. 



103 



of the teeth. Lastly, the true Horse is found just above this 

 horizon, and the series is complete. It appears therefore 

 reasonable to conclude that this series of gradations is best 

 explained by the theory of Evolution. In the same way Dr. 

 Smith Woodward traces upward from small ancestors the 

 gigantic Ground-Sloths and Armadillos of South America, in 

 which the land area may have been more extensive — even per- 

 haps connected with a great Antarctic continent which included 

 Australia — a hypothesis supposed to be favoured by the finding 

 of the large, extinct Horned Tortoise both in Queensland and 

 Patagonia. Moreover, " strange Ungulates (Toxodontia, Typo- 

 theria, and Lipoterna), which in some respects resembled 

 rodents, can also be traced in the same region from small 

 progenitors to gigantic representatives. Some of the Lipo- 

 terna were one-toed, and were curious mimics of the Horse, 

 of the northern hemisphere" 



Further, the riddle of the occurrence of gills in the young of 

 the Land Salamander of the Alps, which never enter the water 

 and of course never use their temporary gills, as also the 

 presence of gill-clefts in the young of the higher vertebrates, is 

 surely fairly read by the supposition or theory that such have 

 probably had aquatic ancestors. 



The Zoea-stage, again, in the young of the Shore-Crab points 

 to a long-tailed progenitor ; just as the birth of the young 

 Flounder in a shape similar to that of a young Cod (and having 

 an eye on each side) indicates theoretically a common ancestry, 

 the turning of the eye to the other (coloured or upper) side 

 being a subsequent adaptation to suit its ground-haunting 

 habits. 



Mr. Darwin and the evolutionists may fairly claim that their 

 hypothesis embraces a greater number of phenomena and sug- 

 gests a more satisfactory explanation of them than any other 

 theory yet propounded. This much even those reared in the 

 schools of Goodsir and Oken, Owen and St. Hilaire, must frankly 

 admit, though, as shown by Prof. Cleland of Glasgow, they 

 must, apart from all external influences, supplement the theory 

 by a definite evolution of organization dependent on a definite 

 cause. While the evolutionary theory explains the order and 

 fitness of the organic beings on the surface of the earth, it does 



