. 11. 



in th* Animal Kingdom. 359 



Fig. ll> represent the common origin, the homogeneous na- 

 ture, and therefore 

 the coincidence, es- 

 sentially, in funda- 

 mental form, of va- 

 rious parts arisingout 

 of the serous lamina 

 of the germinal mem- 

 brane of Man (Plate 

 I, Fig. 3, **):f and 

 firstly, of those parts 

 proceeding, respec- 

 tively, from the la- 

 minae dorsales and 

 ventrales ; constitu- 

 ting as the latter do, an upper and an under tube, (Plate I, 

 Fig. 6, a. b. c.) 



The curves, differing in direction and in length, may illus- 

 trate differences in direction and in degree of development of 

 the vertebrae ; including as well the development of those consti- 

 tuting the coccyx, curve A B, as that of those which, vastly 

 more wrought out, enter into the formation of the cranial bones, 

 curve A E ; the development of the intermediate vertebrae 

 being represented by the intervening curves. J 



The development of the ribs being exhibited by one curve, 

 that of the hyoid bone, lower jaw, &c. may be shewn by others. 

 If the curve A B, represent the development of the spinal 

 cor d, A E may serve to shew that of the most elaborate por- 

 tion of the hemispheres ; and the intervening curves, the deve- 

 lopment of intermediate parts of the cerebro-spinal axis. All 



f The Plate here referred to, is contained in the last number of this Journal 

 $ In our former paper (p. 135) we stated the applicability of the above dia- 

 gram, in a comparison of systems of organs or single organs in different ani- 

 mals. Thus to apply it here ; the curve A, E, representing the development 

 of the cranial bones in Man, A, C, and A, D, may illustrate coresponding 

 parts in osseous Fishes or other Vertebrata, less removed from vertebrae both 

 in direction and degree. 



Referring to the preceding note, we have again an instance in which the 

 curves A C and A D, may illustrate the development of the hemispheres in 

 animals whose brains are less removed from their primitive simplicitv than 

 the brain of Man. 



4ft f 



