382 APPENDIX, 



Figs. A and B are seven times enlarged, Figs. C and I) five times, 

 Figs. E and H four times. Plate II. exhibits the very close blood 

 relationship between birds and reptiles ; Plate III. that between 

 man and the other mammals. 



Plate IV. (Between pages 34 and 35, Vol. II.) 



The Hand, or Fore Foot, of nine different Mammals. This plate 

 is intended to show the importance of Comparative Anatomy to 

 Phylogeny, in as much as it proves how the internal skeleton of 

 the limbs is continually preserved by inheritance, although the 

 external form is extremely changed by adaptation. ' The bones of 

 the skeleton of the hand are drawn in white lines on the brown 

 flesh and skin which surrounds them. All the niue hands are 

 represented in the same position, namely the wrist (where the arm 

 would be joined to it) is placed above, whilst the ends of the fingers 

 or toes are turned downwards. The thumb, or the first (large) 

 fore-toe is on the left in every figure ; the little finger, or fifth toe 

 is to the right at the edge of the hand. Bach hand consists of 

 three parts, namely (i.) the %vrist (carpus), composed of two cross 

 rows of short bones (at the upper side of the hand) ; (ii.) the 

 mid-hand (metacarpus), composed of five long and strong bones 

 (marked in the centre of the hand by the numbers 1-5) ; and 

 (iii.) the five fingers, or fore toes (digiti), every one of which 

 again consists of several (mostly from two to three), toe-pieces, 

 ov phalanges. The hand of man (Fig. 1), in regard to its entire 

 formation, stands mid- way between that of the two large human 

 apes, namely, that of the gorilla (Fig. 2), and that of the 

 orang (Fig. 3). The fore paw of the dog (Fig. 4), is more 

 different, and the hand or breast fin of the seal (Fig. 5) still 

 more so. The adaptation of the hand to the movement of swim- 

 ming, and its transformation into a fin for steering, is still more 

 complete in the dolphin (Ziphius, Fig. 6). The extended fingers 

 and bones of the central hand here have remained short and strong 

 iu the swimming membrane, but they have become extremely long 

 and thin in the hat (Pig. 7), where the hand has developed into 

 a wing. The extreme opposite of the latter formation is the hand 



