74 FIELD AND FOREST. 



that there are certain very definite regions in which, severally, animals 

 are segregated from all others ; that those regions and the irmutual re- 

 lations are equally indicated by all classes of animals; and that the 

 distribution of marine animals is collateral with that of inland forms. 

 But little knowledge of (acts and little reflection is necessary to render 

 obvious the fallacy of these views. 



The regions, or realms as some would call them, defined by Mr. 

 Wallace have been just specified. Their bounds are in several instan- 

 ces disputable, and would be more or less modified by students of dif- 

 ferent classes, as Mr. Wallace, in fact, admits. The marches between 

 contiguous regions in which species of the two commingle on com- 

 mon ground may be many hundreds of miles in width. In few cases, 

 indeed, except when bordered by the wide ocean, are the exact limits 

 of the regions defined, or, it may be added, will ever be definable. 

 We should be amiss even if we looked to the highest mountains as in- 

 variable dividing lines. The Rocky Mountains, for example, do not 

 at all trenchantly separate the " eastern " and " western " regions, as 

 is alleged by Mr. Wallace (v. i. p. 6), but the plains west of the Mis- 

 sissippi form neutral ground intervening between the two. The dif- 

 ferences between the Atlantic and Gulf slopes on the one hand and the 

 Pacific and Rocky r Mountain on the other are rather, at least to a 

 considerable extent, attributable to the " mediterranean " seas which 

 in tertiary times covered so great a portion of the present hydrograph- 

 ical basin of the "Mississippi" rivers. The new-made land was 

 apparently mostly colonized from the eastern and northern regions, 

 and the subsequent commingling of types, extensive as it has been, 

 has still not obliterated the primeval diversity between the two, al- 

 though this is now most distinctly exemplified by the fishes. 



Toads as Pets. — -A correspondent of the Gardener s Chronicle 

 speaking of pets, says: "My first. attentions were devoted to toads,, 

 and very (ew persons can believe how much an unpreposessing creature 

 of this kind can be taught. I had five ; they knew me perfectly ; they 

 knew their own names, &c." The editor of this journal is reminded 

 by the above that toads were among his earliest pets, and that they, 

 too, knew their names, and learned to come when called. 



