PROGRESS OF ANIMAL MORPHOLOGY. 481 



nent in inferior animals. Thus, according to this view, the human 

 fetus assumes successively the plan of the zoophyte, the worm, the 

 fish, the turtle, the bird, the beast. But it has been well observed, 

 that " in these analogies we look in vain for the precision which can 

 alone support the inference that has been deduced ;" 1S and that at 

 each step, the higher embryo and the lower animal which it is 

 supposed to resemble, differ in having each different organs suited to 

 their respective destinations. 



Cuvier 14 never assented to this view, nor to the attempts to refer the 

 different divisions of his system to a common type. " He could not 

 admit," says his biographer, " that the lungs or gills of the vertebrates 

 are in the same connexion as the branchiae of molluscs and crustaceans, 

 which in the one are situated at the base of the feet, or fixed on the 

 feet themselves, and in the other often on the back or about the arms. 

 He did not admit the analogy between the skeleton of the vertebrates 

 and the skin of the articulates ; he could not believe that the taenia and 

 the sepia were constructed on the same plan ; that there was a similar- 

 ity of composition between the bird and the echinus, the whale and 

 the snail ; in spite of the skill with which some persons sought gradu- 

 ally to efface their discrepancies." 



Whether it may be possible to establish, among the four great divi- 

 sions of the "Animal Kingdom," some analogies of a higher order 

 than those which prevail within each division, I do not pretend to con- 

 jecture. If this can be done, it is clear that it must be by comparing 

 the types of these divisions under their most general forms : and thus 

 Cuvier's arrangement, so far as it is itself rightly founded on the unity 

 of composition of each branch, is the surest step to the discovery of a 

 unity pervading and uniting these branches. But those who general- 

 ize surely, and those who generalize rapidly, may travel in the same 

 direction, they soon separate so widely, that they appear to move 

 from each other. The partisans of a universal "unity of composition" 

 of animals, accused Cuvier of being too inert in following the progress 

 of physiological and zoological science. Borrowing their illustration 

 from the political parties of the times, they asserted that he belonged 

 to the science of resistance, not to the science of the movement. Such 

 a charge was highly honorable to him; for no one acquainted with 

 the history of zoology can doubt that he had a great share in the 

 impulse by which the " movement " was occasioned ; or that he him- 



13 Dr. Clark, p. 114. M Laurillard, Elog. de Cuvier, p. 66. 



VOL. II. 31. 



