OBJECTIONS TO THE THEORY OF NATURAL SELECTION 205 



throw very little light on our subject. Excluding such cases of 

 abrupt variations, the few which remain would at best constitute, 

 if found in a state of nature, doubtful species, closely related to 

 their parental types. 



My reasons for doubting whether natural species have changed 

 as abruptly as have occasionally domestic races, and for entirely 

 disbelieving that they have changed in the wonderful manner indi- 

 cated by Mr. Mivart, are as follows: According to our experience, 

 abrupt and strongly marked variations occur in our domesticated 

 productions, singly and at rather long intervals of time. If such 

 occurred under nature, they would be liable, as formerly explained, 

 to be lost by accidental causes of destruction and by subsequent 

 intercrossing; and so it is known to be under domestication, unless 

 abrupt variations of this kind are specially preserved and sepa- 

 rated by the care of man. Hence, in order that a new species should 

 suddenly appear in the manner supposed by Mr. Mivart, it is 

 almost necessary to believe, in opposition to all analogy, that 

 several wonderfully changed individuals appeared simultaneously 

 within the same district. This difficulty, as in the case of uncon- 

 scious selection by man, is avoided on the theory of gradual evolu- 

 tion, through the preservation of a large number of individuals, 

 which varied more or less in any favorable direction, and of the 

 destruction of a large number which varied in an opposite manner. 



That many species have been evolved in an extremely gradual 

 manner, there can hardly be a doubt. The species and even the 

 genera of many large natural families are so closely allied together 

 that it is difficult to distinguish not a few of them. On every con- 

 tinent, in proceeding from north to south, from lowland to upland, 

 etc., we meet with a host of closely related or representative 

 species ; as we likewise do on certain distinct continents, which we 

 have reason to believe were formerly connected. But in making 

 these and the following remarks, I am compelled to allude to sub- 

 jects hereafter to be discussed. Look at the many outlying islands 

 round a continent, and see how many of their inhabitants can be 

 raised only to the rank of doubtful species. So it is if we look to 

 past times, and compare the species which have just passed away 

 with those still living within the same areas; or if we compare the 

 fossil species embedded in the sub-stages of the same geological 

 formation. It is indeed manifest that multitudes of species are 

 related in the closest manner to other species that still exist, or 

 have lately existed; and it will hardly be maintained that such 

 species have been developed in an abrupt or sudden manner. Nor 

 should it be forgotten, when we look to the special parts of allied 



