DESIGN A PROMINENT FACTOR IN NATURE 363 



and moisture in the localities in which they are found is apparent from this, that in mountainous regions there are 

 belts of vegetation in which particular trees and shrubs flourish ; each zone of vegetation characteristically differing 

 from the others. Thus the highest zones produce plants and animals whose homes are in northern cHmates — for 

 example, the arctic regions ; the lower zones producing such only as are found in warmer climates, tropical, sub- 

 tropical, or otherwise, in different parts of the earth. When, in mountainous districts, the snow hne is reached, 

 only mosses and the meanest and hardiest plants are met with. The giant trees and tall shrubs are found at lower 

 levels, where the chmate is milder. The geological record testifies to the same thing in animals. Remains of 

 whales have been dug up in the valley of the Tay in the vicinity of Perth, Scotland ; and Mastodons have been 

 exhumed in the valley of the Thames, near London, England. These two facts conclusively go to show that the 

 chmate of Great Britain has been at one time arctic in character, and at another, tropical or semi-tropical. 



Plants and animals are adapted to their habitats by the Great Designer, but they have also, up to a point, 

 a power of adaptation in themselves. The rhinoceros was originally and is now a typical tropical or semi-tropical 

 smooth-skinned pachyderm. When it migrated northwards, which it did at one period, to a colder chmate, it grew 

 hair, and hence the woolly species. The same is true of certain of the elephant tribe, which acted in a precisely 

 similar fashion. The Mastodon had a hairy integument. The negro, who inhabits various parts of Central Africa 

 and who is exposed to excessive heat, has developed a thick, oily skin crowded with dark pigment, woolly hair, and 

 a comparatively thick skull. These changes in the skin and hair of the rhinoceros, the elephant, and the negro 

 are largely due to the operation of external influences. They are also traceable to a power of accommodation 

 inhering in the individuals themselves. Moreover, the changes are httle more than skin deep. The negro remains 

 a man, and the woolly rhinoceros and hairy elephants have not parted with their distinguishing characteristics. 

 Environment invokes, rather than causes, shght modifications in plants and animals. If more be conceded, mere 

 externahties are accredited with powers they do not really possess : the externalities usurp the prerogatives of fife. 

 In other words, modifications in plants and animals come from within more than from without. Mere environment 

 can achieve nothing. The question in every case comes to be. Can plants and animals modify and accommodate 

 themselves to their surroimdings and five, or must they go to the wall and die because of their inabiHty to modify 

 sufficiently ? One often hears environment spoken of as the chief factor in the modification of plants and animals, 

 but it is safe to assert that environment never leads. All modifications, be they great or small, begin and terminate 

 in the plants and animals themselves. In order to give undue prominence to the power of environment, those who 

 theorise on this subject assume that plants and animals are provided with irritable constitutions, and external sur- 

 faces which are influenced by stimuU supphed by environment. They largely ignore the vital and sensitive powers 

 of plants and animals, and regard plants and animals as mere machines or automata, which they certainly are not. 



I have alluded to the power of growth and reproduction in plants and animals, and there is perhaps no subject 

 in the whole range of physiology in which design and the persistent nature of types can be more readily and satis- 

 factorily made out. Growth and reproduction are fundamental in their nature. Like produces like, both in 

 plants and animals. However much germs, seeds, and eggs may resemble each other even under the highest 

 powers of the microscope, they essentially and materially difier. An orchid cannot be produced from the seed of 

 a wallflower, neither can an aUigator be produced from the egg of a fish, or a giraffe from the ovum of a hon. The 

 essential differences which meet us at the very beginnings of Ufe must be admitted and faced, whatever the micro- 

 scope says and whatever ultimate chemical analysis says. The microscope, chemical analysis, and human vision 

 aided and unaided, are incompetent to distinguish and demonstrate the difference, but the adult plants and animals 

 testify to an inherent dissimilarity which makes them what they are, and which has distingtiished them from the 

 moment the male and female elements came together and made reproduction possible. Every germ, seed, and egg 

 (and the same is to be said of the male elements where they exist) have characteristics which cannot be ignored or 

 set aside. The division of plants and animals into famiUes, orders, genera, and species depends upon this difference. 



Some investigators, bent on simpHfying the mysteries and complexities of nature, have ventured to assert 

 that all plants and animals proceed from protoplasm which is absolutely homogeneous and identical in all its parts 

 and particles. This view is A friori unthinkable. The same protoplasm, placed in exactly the same conditions 

 of heat, air, moisture, &c., would produce only one kind of plant or one kind of animal. It would be impotent and 

 wholly inadequate to produce the leading races of the vegetable and animal kingdom. To have a legitimate dis- 

 tinction, there must be an actual difference, and the obvious inference is, that the great races of plants and animals 

 differ because their male and female elements (which are their most essential parts) differ. 



If for the sake of argument it be admitted that the ovum or female element in plants and animals is homo- 

 geneous and identical, then it must be conceded that the male element, in whatever form it appears, is characteristi- 

 cally and fundamentally different. From male and female homogeneous absolutely identical elements, as already 

 stated, only one kind of plant or animal could possibly proceed. The beginnings of plants and animals are in every 



