36 THE PRINCIPLE OP Chap. I. 



numerous muscles. Respiration is partly voluntary, but 

 mainly reflex, and is performed in the most natural and 

 best manner without the interference of the will. A vast 

 number of complex movements are reflex. As good an 

 instance as can be given is the often-quoted one of a 

 decapitated frog, which cannot of course feel, and cannot 

 consciously perform, any movement. Yet if a drop of 

 acid be placed on the lower surface of the thigh of a 

 frog in this state, it will rub off the drop with the upper 

 surface of the foot of the same leg. If this foot be cut 

 off, it cannot thus act. " After some fruitless efforts, 

 therefore, it gives up trying in that way, seems restless, 

 as though, says Pfliiger, it was seeking some other way, 

 and at last it makes use of the foot of the other leg and 

 succeeds in rubbing off the acid. Notably we have here 

 not merely contractions of muscles, but combined and 

 harmonized contractions in due sequence for a special 

 purpose. These are actions that have all the appear- 

 ance of being guided by intelligence and instigated by 

 will in an animal, the recognized organ of whose intelli- 

 gence and will 'has been removed." 10 



We see the difference between reflex and voluntary 

 movements in very young children not being able to 

 perform, as I am informed by Sir Henry Holland, cer- 

 tain acts somewhat analogous to those of sneezing and 

 coughing, namely, in their not being able to blow their 

 noses (i. e. to compress the nose and blow violently 

 through the passage), and in their not being able to clear 

 their throats of phlegm. They have to learn to perform 

 these acts, yet they are performed by us, when a little 

 older, almost as easily as reflex actions. Sneezing and 

 coughine:, however, can be controlled bv the will onlv 

 partially or not at all: whilst the clearing the throat 



10 



Dr. Maudsley, ' Body and Mind,' 1870, p. 8. 



