THE HAMILTON ASSOCIATION. 29 



and then consider if we have not got in all this a cause abundantly 

 sufficient to account for all the puzzling and perplexing variations 

 and modifications that we find in the species of the present day. It 

 appears to me that the wonder ceases to be that they are so many, 

 and the surprise comes in rather that their should be any stability 

 left in any organism whatever, and I quite believe there would 

 be none, but for the yet more marvellous power of hereditary trans- 

 mission that holds every living form true to the species from which it 

 came and from which it has not the power nor possibility of escape, 

 and which alone makes classification possible. 



Man produces his artificial varieties through his intelligent con- 

 trol of the natural laws of generation and propagation. Nature 

 originates its varieties through the external influences of diverse 

 geographical and geological conditions, and multiplies them by a 

 commingling of these. Natural selection, as distinguished from 

 artificial, begets promiscuous commingling of a species, and the 

 power of environment produces the comparative uniformity in nature 

 that we see. Natural selection, combined with external local 

 influences, produces the local flora and fauna, which we can arrange, 

 classify and systematize, and it is to a commingling of these diverse 

 forms, producing a multitude of transmittable possibilities in the 

 organization, that we may have to attribute many of those occasional 

 and oft surprising differences that we find it so difficult to classify. 



When contemplating any of the living forms of the present, and 

 considering as to how it came to be as it is, we have to take into 

 account not only its present existence and existing conditions, but 

 also when and where it may have originated, the locality from which 

 it may have come, and the direction in which it may have travelled. 

 We have to think of the time that has elapsed since it was first 

 originated, of the hundreds and thousands of generations which 

 have come and gone since then, of the thousands of diverse influ- 

 ences that have encompassed and pressed in on every side in its 

 onward course, moulding and modifying it in so many imperceptible 

 and unsuspected ways. How it may have been held for thousands of 

 years under one set of influences, and thousands of years under 

 another, and as many more under a third, whilst during all these 

 thousands of years it was mingling its diverse forms and producing 

 yet more diversity, and this specimen which we are naming may be 

 one of the last that has appeared in this seemingly interminable line 



