Inheritance of Acquired Characters 247 



2. Remaining surface of digits, middle of forehead, olecranon. 



3. Glabella, chin, clavicle. 



4. Palm, buttock, popliteal space. 



5. Neck. 



6. Back. 



7. Lower eyelid, cheek. 



8. Nipple, loin. 



These two tables show the great differences in the range 

 of sensitiveness to cold and to warmth in different parts of 

 the body. I doubt if any one will attempt to show that 

 these differences of range of sensation can be accounted for 

 either by natural selection or by the Lamarckian hypothesis. 



Of course, it does not necessarily follow that, because this 

 is true for the warm and cold spots, that it must also be true 

 for the tactile organs; but I think that the fact of such a great 

 difference in the responsiveness to cold and to warmth in 

 different parts of the body should put us on our guard against 

 a too ready acceptation of Spencer's argument. More espe- 

 cially is this seen to be necessary, when, as has been shown 

 above, the distribution of the touch-organs themselves by no 

 means closely corresponds to what we should expect, if they 

 have developed in response to contact, as Spencer maintains. 



The other main argument advanced by Spencer to fortify 

 the theory of the inheritance of acquired characters, and at 

 the same time to show the inadequacy of the theory of natu- 

 ral selection, is based on the idea of what he calls the " co- 

 operation of the parts " that is required in order to carry out 

 any special act. Spencer contends that " the relative powers 

 of cooperative parts cannot be adjusted solely by the sur- 

 vival of the fittest, and especially where the parts are nu- 

 merous and the cooperation complex." 



Spencer illustrates his point by the case of the extinct 

 Irish elk, whose immensely developed horns weighed over 

 a hundredweight. The horns, together with the massive 

 skull, could not have been supported by the outstretched 



