86 HISTORY OF PHYSIOLOGY. 



much more clear, if we consider what it excludes and denies. It rejects 

 altogether all conception of a plan and purpose in the organs of ani- 

 mals, as a principle which has determined their forms, or can be of 

 use in directing our reasonings. " I take care," says Geoffroy, " not 

 to ascribe to God any intention."* And when Cuvier speaks of the 

 combination of organs in such order that they may be in consistence 

 with the part which the animal has to play in nature ; his rival 

 rejoins, 10 I " know nothing of animals which have to play a part in 

 nature." Such a notion is, he holds, unphilosophical and dangerous. 

 It is an abuse of final causes which makes the cause to be engendered 

 by the effect. And to illustrate still further, his own view, he says, "I 

 have read concerning fishes, that because they live in a medium which 

 resists more than air, their motive forces are calculated so as to give 

 them the power of progression under those circumstances. By this 

 mode of reasoning, you would say of a man who makes use of crutches, 

 that he was originally destined to the misfortune of having a leg para- 

 lysed or amputated." 



How far this doctrine of unity in the plan in animals, is admissible 

 or probable in physiology when kept within proper limits, that is, when 

 not put in opposition to the doctrine of a purpose involved in the plan 

 of animals, I do not pretend even to conjecture. The question is one 

 which appears to be at present deeply occupying the minds of the most 

 learned and profound physiologists ; and such persons alone, adding 

 to their knowledge and zeal, judicial sagacity and impartiality, can tell 

 us what is the general tendency of the best researches on this subject. 11 

 But when the anatomist expresses such opinions, and defends them by 

 such illustrations as those which I have just quoted, 12 we perceive that 

 he quits the entrenchments of his superior science, in which he might 



9 " Je me garde de preter a Dieu aucune intention." Phil. Zool. 10. 

 J0 " Je ne connais point d'animal qui DOIVE jouer un role dans la nature." 

 p. 65. 



11 So far as this doctrine is generally accepted among the best physiologists, 

 we cannot doubt the propriety of Meckel's remark, (Comparative Anatomy, 

 1821, Pref. p. xi.) that it cannot be truly asserted either to be new, or to be 

 peculiarly due to Geoffroy Saint-Hilaire. 



12 It is hardly worth while answering such illustrations, but I may remark, 

 that the one quoted above, irrelevant and unbecoming as it is, tells altogether 

 against its author. The fact that the wooden leg is of the same length as the 

 other, proves, and would satisfy the most-incredulous man, that it was intended 

 for walking. 



