the Megatherium. 367 



occur together with those of gigantic herbivorous marsu- 

 piads ; and there is similar evidence that the Apteryx existed 

 with the Dinornis ; and the author offered the following sug- 

 gestions as more applicable to, or explanatory of, the pheno- 

 mena than the theory of transmutation and degradation. He 

 observed that in proportion to the bulk of an animal is the 

 difficulty of the contest which, as a living being, it has to 

 maintain against the surrounding influences which are ever 

 tending to dissolve the vital bond, and subjugate the organ- 

 ized matter to the ordinary chemical and physical forces. 

 Any changes, therefore, in the external circumstances in 

 which a species may have been created to exist, will militate 

 against that existence, in probably a geometrical ratio to 

 the bulk of such species. If a dry season be gradually pro- 

 longed, the large mammal will suffer from the drought sooner 

 than the small one ; if such alteration of climate affect the 

 quantity of vegetable food, the bulky Herbivore will first feel 

 the effects of the stinted nourishment ; if new enemies are 

 introduced, the large and conspicuous quadruped or bird will 

 fall a prey, whilst the smaller species might conceal them- 

 selves and escape. Smaller quadrupeds are usually, also, 

 more prolific than larger ones. The actual presence, there- 

 fore, of small species of animals in countries where the larger 

 species of the same natural families formerly existed, is not 

 to be ascribed to any gradual diminution of the size of such 

 larger animals, but is the result of circumstances which may 

 be illustrated by the fable of the "oak and the reed" — the 

 small animals have bent and accommodated themselves to 

 changes under which the larger species have succumbed. 



On the Slow Elevation and Subsidence of the Land in Switzer- 

 land. By Prof. B. Studer. 



1. In the neighbourhood of the Alps, the molasse has a 

 thickness of from 1000 to 1500 feet, which decreases in pro- 

 portion to its distance therefrom. The marine organic re- 

 mains present the same species throughout, although there 

 are several intercalated beds of freshwater origin ; and from 

 this, in connection with other facts, we regard the molasse 



VOL. LI, NO. CII. — OCTOBER 1851. 2 A 



