2l8 



DESIGN IN NATURE 



the horse there is a diminution in the number of osseous and other parts, a contraction of the traveUing area, 

 and a concentration of power in certain bones, which are greatly enlarged and thickened for a specific purpose 

 (Plate Ixxvi., Fig. B). In the case of wings, especially those adapted for flying under water and divmg ^ (Plate 

 1 Fia 1, J),' the same features are to be noted, namely, diminution in the number of the bones of the wing, 

 contraction of the osseous wing-area, and a concentration of power in certain wing bones which act screw-fashion 

 in sub-aquatic flight. Nor does the matter rest here in the case of birds which fly in the air. While the skeleton 

 of the wing of the air-flying bird is being simplified by the fusion of certain of its bones, and its actual osseous area 

 reduced its covering of feathers, especially the primary, secondary, and tertiary ones, which are the immediate 

 organs of aerial flight, is being much differentiated and greatly amplified to perfect it as an air-flying organ (Fig. 42). 

 All this means design, modification, and adaptation as apart from mere evolution as such. There can be no 



better examples of design given than are aftorded by 

 the wings and the legs and feet of birds as shown at 

 Figs. 42 and 43. In these figures I have had depicted 

 from nature, and according to scale, the outer portion 

 of the right wing of the whooper swan, an air-flying 

 bird, and the right leg and foot of the ostrich specially 

 modified to walk and run on sand. The wing is a 

 marvel of design. Its bones are twisted and spirally 

 arranged. It is a screw structurally and functionally. 

 It makes a flgure-of-8 track in space in stationary, 

 and a spiral, waved track in free flight. The wing 

 feathers (primary, secondary, and tertiary) are beauti- 

 fully graduated as regards length, direction, and 

 strength. They are elastic, and taper from the roots 

 to the tips. The primary feathers are slightly twisted 

 in the direction of their length, and the primary, 

 secondary, and tertiary feathers are set at various 

 anoffes, and are geared to each other and overlap in 

 such a way that they open during the up-stroke of 

 the wing and close during its down-stroke. They thus 

 alternately evade and seize the air. The opening of 

 the feathers corresponds with the folding of the wing 

 and the up-stroke, and the closing of the feathers 

 with the extension of the wing and the down-stroke. 

 The arrangements are the most intricate and perfect 

 possible. Shall we be told that the wing, a compli- 

 cated and inimitable structure largely developed before 

 the bird is hatched out, is a chance product, the out- 

 come of environment and of a groping, eyeless evolu- 

 tion ? What is said of the wing of the bird applies 

 equally to the legs and feet. The legs may be long as in running, wading birds, or short as in swimming birds : the 

 feet may possess two, three, or more digits, and they may bear claws as in the birds of prey, or webs as in swimming 

 birds. The legs and feet, Uke the wings, are modifled, and adapted to perform certain functions. They also afford 

 proofs of design, to the exclusion of evolution as a bUnd factor in the production of specific structures, the 

 functions of which are obvious and he on the surface. Evolution, it is said, makes for progress, but it has not 

 been shown that the modern horse is a more perfect animal than the five-toed mammal, its supposed ancestor ; or 

 that the modifications in the limbs of birds are not as great, or even greater, than those which occur in the horse. 

 The order of the organic kingdom is one of gradation, and it may be quite a fallacious interpretation of the facts 

 to say that the so-called connecting links are not as important in their way as the great groups themselves. This 

 remark apphes to development as a, recognised part of gradation. The mere number of individuals in a group, as 

 1 have pointed out, does not invalidate the distinction here drawn. From a careful and extended study of the 

 subject I am disposed to beheve that the hmbs and soUd hoofs of the horse tribe are not the outcome of evolu- 

 tion, but are special developments, modifications, and adaptations to ensure strength, and to increase speed on 



1 In tliF case of bird.s wliich Hy in the air, tlie area of the wing is greatly increased by the addition of feathers, namely the primary, secondary 

 and tertiary feathers ; these being chiefly engaged in aiirial tiight, " ' J> 



Via. 42. — Skeleton of tlie outer portion of the right wing of tlie wliooper 

 swan {C'ygnus musicus). Shows that the bones of the hand and phalanges 

 (finger bones) are very gieatly modified ; certain of the bones being sup- 

 pressed and others greatly enlarged, strengtliened, and soldered together 

 to form a flat osseous platfonn for supporting the roots of the primary 

 and secondary feathers which are especially engaged in aisrial flight 

 g. Ulna ; h, radius ; i, radio-ulna-carpo articulation ; u, earpo-nietacarpus ; 

 p, first digit or thumb ; q, second digit ; /•, tliird digit. Drawn from nature 

 by C. Berjeau for the present work. 



Fii;. 43. — Portion of the right leg and foot of the ostrich (Stnithio 

 camelus). The foot of the ostrich displays two toes, and is most interesting, 

 as it fomis a transition link between the great extinct moa {Dinornis 

 (liganteus), which had four toes, and the modern emu (Dromseiis novn-'- 

 lioU anility), which has three toes. The dropping of toes in the ostrich tribe 

 is quite as remarkable as tlie dropping of toes in the horse, n. Major toe 

 of the ostrich, whicli does tlic principal part of the walking and running ; 

 J, minor or subsidiary toe, which takes little part in locomotion ; c, lower 

 part of leg. Drawn from nature by C. Beijeau for the iiresent work. 



