EX VI RIB US VIVIMUS. 



animals man seems never to have selected or en- 

 deavoured to produce longevity, probably because 

 of its uselessness ; had he done so, vs^e might hope 

 for some valuable facts from his experiments. 



With regard to observations on the length of life of 

 other animals, the certain knowledge is very small, 

 only that tenure of life which is very brief being 

 easily observed.^ The greatest uncertainty or even 

 ignorance prevails as to the duration of life of even 

 the commonest mammals, birds, and fishes ; in most 

 cases it seems only possible to say that it is not less 

 than a certain period. This of course furnishes a 

 limited means of comparison. A writer in the ' Eng- 

 lish Cyclopsedia'^ says: 'Of the age to which the 

 horse would naturally arrive, it is impossible to say 

 anything satisfactory. Many have exceeded thirty, 

 and some of them even forty, but from ill usage and 

 over-exertion the majority come to their end before 

 they have seen nine or ten years.' M. Flourens gives 

 exceedingly wide ranges for many mammals in his 

 book above noted, whilst it is obvious, if we consider 

 the position of many wild animals, such as the larger 



' We may naturally suppose that if we are ignorant with regard to 

 man to the extent above shewn, still more a fortiori shall we be ignorant 

 as to wild animals, to none of which has statistical examination been 

 applied, nor probably can be in any but the rarest cases. It is clear, 

 since animals do not carry the number of the years of their proper life 

 marked on their bodies, like any of those specific characters which are struc- 

 tural, we can only form guesses as to this period from individual cases. 



' C. Knight's ' English Cyclopaedia,' Article ' Horse.' 



