664: .Dynamic Theory. 



it would be swallowed and digested, but in order to make an effort to 

 take food to put into the mouth, there must be a memory of the relation- 

 ship between the food and the feeling of satisfaction which follows the 

 eating of it, which memory belongs to the missing hemispheres. In 

 other words, the track for the stimulations from food not in actual con- 

 tact with the organs of deglutition to the motor nerves concerned in 

 appropriating it, is through the cerebrum. The food is doubtless seen, 

 but it is seen as an obstruction to be avoided, if in the way, or, if out 

 of the way, as having no relationship whatever to the fish. The sense 

 of smell is not operative, as the olfactory lobe has direct connections 

 only with the hemispheres, and this sense is largely concerned in the 

 fish's quest of food. And here we may again insist upon the hoino- 

 geneousness existing between the habits upon which are founded the 

 functions called reflex and those called purposive. In an unmutilated 

 fish a stimulation going from an object, which may be either an obstruc- 

 tion or an article of food, passes to the eye and optic lobes. It is di- 

 vided, the first part going directly to the medulla oblongata, and thence 

 on to certain muscles and limbs, which are moved in such a manner as 

 to steer the fish away from the body as from an obstruction ; the second 

 part goes to the medulla oblongata by way of the cerebral hemispheres, 

 and passes on to the very same muscles and limbs, and may steer the 

 fish toward the body as to an article of food. Now, when the fish is de- 

 prived of its hemispheres, the influence of the second part of the stim- 

 ulation is annulled, while that of the first part remains in full force and 

 effect. In the second case, we are accustomed to say the fish is gov- 

 erned by a perception of the presence of food. Why have we not as 

 good reason in the first case to say it is governed by a perception of the 

 presence of an obstruction? Yet it is demonstrated that the perception 

 of the obstruction lies, or may lie, exclusively in the optic lobes and 

 the medulla oblongata ; and 'it becomes obvious that while there are two 

 separate machines for these two perceptions, the only difference between 

 them is that the one which perceives that the object is food is somewhat 

 more complicated than the one which only perceives that it is an ob- 

 struction. 



Dr. Ferrier's experiments prove that the action of the cerebrum is re- 

 flex in the same sense as is the action of the spinal cord, medulla ob- 

 longata, cerebellum, optic lobes and corpora striata. Actions which 

 are always recognized as prompted by ideas and emotions, and are the 

 usual " expressions " of these so-called "mental states," are performed 

 in utter unconsciousness, and in the absence of any mental state, as 

 such term is usually understood. The process is exclusively physical; 

 a form of physical energy communicated to the physical organs which 

 constitute the cortex of the cerebrum, produce physical demonstrations. 



