;70 



PEINCIPLES AND METHODS OF PALAJ:ONTOLOGY. 



deficiencies in our knowledge. At the same time, the ipj|niry into the 

 permanence or modifiability of species is, in itself, of the highest import- 

 ance and interest; and it will be ue(!essar.y to advert to the bearings of 

 the little definite evidence Ave at present possess u\Hm the subject in 

 some of the following pages, 



(Here follows in tlie original, on pages xix — xxix, a review of the 

 sub kingdoms and classes of animals: but as there are several disputed 

 points, and as the author him.self has since modified his views, they are not 

 reproduced.) 



The Protozoa, as a whole, are evidently sim])ler in structure and less 

 variously endowed thau the Coehlenterata ; the Coehlenterata than the 

 Mollusca or Annnlom; and none of the last approach either birds or 

 mammals in complexity. 



Again, a lamprey is a simpler animal than a horse, a worm thau a bee. 



These indubitable facts are commonly expressed by the phrase that 

 the simpler aninmls are lower and less perfect than the higher, and this 

 indeed, in one sense, they truly are. But we should greatly err in sup- 

 posing that less j^erfcciion implies imperfection; or in imagining that the 

 less perfect animal is in any way unfitted for the conditions under which 

 it lives. Were it so, its race would necessarily sooner or later cease to 

 exist. If we look closely into the matter, it will be found that by "less 

 perfect" and "low in the scale of life," one of two things is meant, either 

 firstly, that the creature of which the assertion is made is a less compli- 

 cated apparatus; or secondly, that the parts of which it is composed 

 differ from one another comparatively little in form and structure. 



It is Avorth while to consider each of these cases more fully. Every 

 animal (indeed it might be said every living thing) has in the gross the 

 same kind of work to do: it has to take in the food necessary for its 

 support; it has to change this into other i^roductsand to mold them into 

 its own peculiar form. Lastly, it has to exhibit that kind of reaction 

 upon external impressions which is known as " irritability." Absorption, 

 metamorphosis, and irritability, these are the three great " functions" 

 of all animals. 



Now the difference between one animal and another, as to the mode 

 in which the functions are performed, is very similar to the difference 

 which exists between one human society and another, as to the mode in 

 which the affairs of life are carried out. All human wants may be 

 summed up in two Avords : sustenance and freedom ; but the mode in 

 Avhich men secure the satisfaction of their wants varies with the perfec 

 tion of their social state. In saA^age life every man procures his oavu 

 food, and relies for his security from constraint upon the strength of his 

 own arm. But this state of things is manifestly incompatible with any 

 great adA^ance, either in those arts which minister to the physical, or in 

 those which satisfy the moral nature. If a man has to find his food 

 CA^ery day he Avill not spend much time in cooking it ; and if he is liable 

 to be attacked by an enemy at all hours, he is pretty sure never to at- 

 tain to much eminence as a painter or a violinist. By the necessity of 

 the case, then, Avhere every man has to do CA^erything for himself, noth- 

 ing will be done very Avell; no man Avill be much better than another, 

 and none Avill be A^ery far above the level of mere animal existence. 



Contrast this state of things Avith that Avhich obtains among the 

 active members of a highly civilized society, such as our own. Each 

 dcA'otes himself to one occupation, striving to carry out that in the best 

 possible manner; and trusting to others Avho dcA^ote themselves to other 

 specialities for the satisfaction of all the rest of his Avants. There is a 

 " division of labor;" the wants of mankind are split up, as it were, into 



