GEOGRAPHY OF ANIMALS IN SOUTH DEVON. 119 



no intimations of the spread of human agency and 

 ingenuity were perceptible, as for the traveller in the 

 interior of Africa to descry, from the highest moun- 

 tain, these same indications of the presence of his 

 species. We have only to remark, that the opera- 

 tions of tillage, draining, irrigation, fencing, build- 

 ing, and all the manifold improvements and con- 

 veniences suggested by the arts and sciences, for 

 the welfare of mankind, must, without doubt, 

 influence the number of our animals, the increase of 

 certain kinds in preference to others, and the geo- 

 graphical range, and limits of the whole. They 

 consign some to extirpation, or numeral diminution, 

 as to one locality, or as to the county itself, and 

 some are diminished in number but yet enjoy the 

 same general distribution : on the other hand, they 

 encourage the dissemination of very many locally, 

 or generally, by multiplying their resources as to 

 sustenance and protection. It is likewise probable, 

 that not only have the horticultural, and botanical 

 alterations effected, as before said, certain augmen- 

 tations in our list; but here also other human 

 actions may have had a similar result ; but I speak 

 hesitatingly ; at all events it is quite evident that we 

 have lost rather than gained in variety of animals, 

 by these interferences on the part of man : so exten- 

 sive, and general are these interferences, that, in 

 speaking of the geographical range, and habitats of 

 any given species, it would be found vain and futile 

 to endeavour to assign these as they would naturally 

 exist ; excepting perhaps in a few instances, all our 

 land-animals have been interfered with in some 

 way or other ; we dare not divest ourselves of these 

 considerations, they have become important in the 

 history of animals, the speculative industry of hu- 

 manity has exerted a direct influence on the ordi- 

 nances of nature. We cannot speak of the swallow, 

 or martin, without speaking of houses ; we cannot 

 allude to the lark, without alluding to corn-fields ; 

 we cannot refer to the petella fluviatilis, or helix 



