432 NATURE AND MAN. 



while the peculiarities of the special Bird family to which it 

 belongs are the last to make their appearance. Thus, in the lan- 

 guage of the great Embryologist, Von Baer, to whom we owe this 

 splendid generalization, its evolution consists in a gradual progress 

 from the general to the special^ or, as Herbert Spencer would say, 

 from the homogeneous to the heterogeneous. 



Now if, in examining the structure of a typical Bird, we find 

 evidences of " design " in the wonderful adaptation of its clothing 

 of feathers alike to keep in the warmth of the body, and to sustain 

 it in its flight through the air, — in that organization of its heart 

 and lungs which enables them to keep up the energetic circulation 

 and respiration required for the maintenance of a high standard 

 of muscular activity, — in those arrangements of the skeleton and 

 muscular apparatus which give support and motion to the ex- 

 panded wings, — in the adaptation of the eye to that acute and 

 far-ranging vision which is needed for the guidance of its actions, 

 — and in many other provisions I might enumerate, — I affirm, 

 without any doubt of your assent, that this evidence is not in the 

 least degree invalidated by the discovery that the germ-particle is 

 not a miniature bird, but a protoplasmic "jelly-speck." In its 

 capacity for " evolution " into the complete type, the germ-particle 

 is just as much " potentially " the Bn-d, as if it could become one 

 by merely swelling out. 



So, if we go back in thought to the origin of the race, as we 

 can by actual observation to that of the individual, the old con- 

 ception of " design " which was based on the idea of an original 

 Bird-creation does not lose any of its applicability, if we find 

 reason to believe that the orighial progenitor was a protoplasmic 

 "jelly-speck," certain of whose descendants have passed through 

 a series of forms progressively improving in structure and capacity, 

 and culminating in the perfected Bird. We merely substitute for 

 the idea of continuous uniform descent, that of the " progressive 

 development" of the race, as representing the mode in which our 

 present Bird has come to be ; deeming the latter the more prob- 

 able, because we find it correspond with the embryonic history 

 of every Bird now existing. The original progenitor was just as 

 " potentially " the Race, whether called into existence as a proto- 

 plasmic "jelly-speck," or as a fully developed Bird. And the 



