41 ON THE STUDY OF ZOOLOGY 



No subject 1ms been more warmly contested than the 

 doctrine of final causes; which, however, has suft'ered more 

 from the ill-judged efforts of its friends, than from the 

 attacks of its enemies. We can hardly conceive that any 

 person, who did not feel a difficulty in believing that a 

 watch was formed for the purpose of shewing the hour, 

 could seriously doubt that our stomachs were expressly 

 constructed for digestion, our eyes for seeing, and the rest 

 of our organs for tlie purposes which they so admirably 

 fulfil. But one must be very fondly attached to final 

 causes, to persuade himself, as some have done, that the 

 sea is salt to preserve it from putrifying ; that the tides of 

 the ocean are designed to bring our vessels safely into port; 

 that stones are made to build houses with ; and silk-worms 

 created in China to furnish the belles and beaux of Europe 

 with satins. It would be only one step further, to assert 

 that sheep have been formed to be sheared and slaughtered j 

 legs to wear boots; and the nose for spectacles. 



Nothing indeed can be more truly unsatisfactory than 

 the well-meant but worn-out complimentary etTusions we 

 are too often doomed to encounter, which, instead of 

 evincing the wisdom of the creation, shew only the folly of 

 their authors, or at least their misconceptions and short- 

 sighted views. The physico-theologists seem to have con- 

 sidered it their duty to point out the end and purpose con- 

 templated by the Creator in every natural arrangement ; 

 thus, they have sometimes fallen into the laughable absur- 

 dity of expatiating upon the wisdom of certain provisions, 

 which subsequent examination has proved not to exist at all. 



The foot of an hymenopterous insect was described as 

 being perforated in a certain part by minute holes ; — imme- 

 diately a sufficient use was discovered for this structure ; it 

 was described as a no less elegant than wise provision for 

 sifting tlie pollen of plants, and thus applying the fine 



tion from the ordinary arrangement, as occurring in the mole. A branch of 

 the superior maxillary nerve goes to the eye, and forms the retina ; while 

 the optic nerves, about the size of hairs, are entirely unconi;ccted with eacb^ 

 other, and cannot be traced to the eyes. Ibid. p. 341, tab. 3. 



