346 DESIGN IN NATURE 



travelling organs possessed by animals in each particular case. Locomotion, primarily and essentially, resolves 

 itself into action and re-action, and it is in every instance a question of power, speed, and support. The quicker 

 the travelling organs are moved the greater the recoil and support obtained from the fulcra on which they act. In 

 flight, if small wings are driven at a very high speed they give as much support as larger wings driven more slowly. 

 If water, which is virtually incompressible, be struck very hard, it affords nearly as much resistance and recoil as 

 a sohd. If air, which is very highly compressible, be similarly treated it also furnishes quite an extraordinary 

 amount of recoil and resistance. Flight were otherwise impossible. To fly is equivalent to walking or swimming 

 in the air. 



When the niceties of construction involved in water and air breathing, in the size, shape, power, and variety of 

 the travelling organs required for effective land, water, and air transit are taken into account, one is forced to conclude 

 that nothing short of an intelligent First Cause and design will satisfactorily account for the existence of the breathing 

 apparatus and organs of locomotion. The means and the ends are so accurately adapted to each other, and the 

 conditions are so rigorously and uncompromisingly exact, that no other explanation is possible. That the arrange- 

 ments necessary for water and air breathing, and for land, water, and air transit were brought about by accident, as 

 those who believe in spontaneous generation affirm, or by the accumulation of fortuitous increments extending over 

 vast periods, according to evolution and " natural selection," is in the highest degree improbable — so improbable 

 indeed as not to be worthy of serious consideration. The theories of spontaneous generation, evolution, and natural 

 selection are utterly inadequate to explain such problems, and, if we ignore a First Cause and design, and law and 

 order as the outcome of both, not only is no explanation forthcoming, but the whole subject becomes unthinkable. 



A great object lesson is afforded by the breathing arrangements, and by the size, shape, and movements of the 

 travelling organs of animals. These can only be regarded as original, fundamental endowments. They admit of 

 no temporising. An animal cannot at one and the same time be a water and air breather ; neither can it progress 

 equally efficiently on the land, on and in the water, and in the air. The physical conditions prevent such a state 

 of things. Little reflection is required to be convinced that in locomotion the cause must be equal to the effect. 

 It works out in a very simple manner. The small feet of land animals when apphed to a rigid unyielding fulcrum, 

 such as the earth, at once obtain support and the recoil necessary to forward movement. In like manner, the tails 

 and fins of fishes (especially the tails), when apphed by reciprocating movements to the yielding aqueous fulcrum, 

 ehcit the recoil necessary to convert them into powerful propellers. Similarly, the comparatively very large wings 

 of the insect, bird, and bat, when made to vibrate rapidly in the air, extract from it the recoil calculated to propel 

 the bodies to which they are attached at high velocities. On the land, support is guaranteed ; propulsion only being 

 required. In the water, support is also guaranteed, from the fact that the swimming creature is of nearly the same 

 specific gravity. The fish, consequently, has only to propel itself. In the air, next to no support is afforded, and the 

 wings have at once to support and propel. These are physical conditions which cannot be ignored. 



Three things require to be attended to in animal locomotion ; namely, (a) the medium to be traversed ; 

 (b) the size, shape, and nature of the travelhng organs ; and (c) the power or force by which the travelhng organs 

 are driven. The feet of land animals are generally small, jointed, springy organs ; the tails and fins of fishes are 

 expanded, finely tapering, elastic structures of a more or less triangular shape ; and the wings of insects, birds, and 

 bats, which are still more expanded, greatly resemble in shape, properties, and functions the caudal and pectoral 

 fins of fishes. The travelhng organs are carefully adapted to the work they have to perform. As a matter of 

 fact, they are designed and elaborately constructed organs. The small feet adapted for land transit are not effective 

 as swimming organs, neither are the tails and fins of fishes of any use as flying organs. 



There is a general rough resemblance as between land, water, and air as media for the travelling organs of 

 animals, and as between the travelling organs themselves. Dry land for example may shade off into marshy soft 

 land ; or water may be solid or semi-solid from freezing ; or it may be semi-solid as in snow and sleet ; or it may 

 be attenuated as in steam by the administration of air. In all these cases the breathing and locomotory organs must 

 be specially modified. The feet of land animals may become expanded and webbed to deal with marshy soil and 

 water, and the pectoral fins of fishes may increase in size as in the flying fish, and deal with the air after the manner 

 of wmgs. Land animals may also essay flight by means of expanded integuments, as happens in the flying dragons, 

 flymg lemurs, and bats. These are the exceptions to prove the rule. The modifications of the travelling organs are 

 as mexorable, m their way, as the breathing arrangements. Indeed, the whole animal must be designed to play 

 a perfectly distinct role as a water or air breather, and as a denizen of the land, the water, or the air respectively. 

 The peculiarities of function must be stiucturally provided for in advance in the embryo and foetus. Nothing 

 is or can be left to chance. Chance in such important and vital matters is out of the question. 



The foregoing remarks on the travelling organs apply more especially to the higher animals, but they are apph- 

 cable m principle also to those of the lower and lowest animals. Every animal, even the most rudimentary is endowed 



