CHAP, x.] OF THOUGHT. 431 



sciousness have their seat in the nervous cells. In effect, where- 

 ever there are phenomena evidently conscious, there are nervous 

 centres. Thought is assuredly a property of the nervous cell. 

 There are conscious nervous cells, and without them there is no 

 psychical phenomenon humble or sublime. This is the idea 

 which the Greek expressed in an ingenious allegory, by making 

 Minerva spring from the brain of Jupiter. The existence of 

 these nervous cells is a necessary condition to the production of 

 the phenomena of consciousness, but the mode in which they are 

 grouped is only a secondary condition of thought. The latter 

 exists with all its principal modes in the nervous ganglionary 

 chapelet of the ant as well as in the brain of the mammif ers. 

 Nevertheless, it is a biological law, that the concentration of 

 nervous cells in great masses is favourable to the development 

 and intensity of the psychical phenomena. The caterpillar has 

 more ganglions than the perfect insect ; the more intelligent the 

 insect is, the larger the cerebroidal ganglion. Finally, in the 

 vertebrated animals, the intellectual development is large in 

 proportion as the encephalon is more voluminous. 



Must we consider the nervous ganglions of the invertebrated 

 animals as so many little brains ? Has each swelling of the 

 central nervous chain, in insects, for example, the faculty of 

 feeling, thinking, wishing, on its own account 1 Is all this gang- 

 lionary concatenation a nervous federation, each member of which 

 enjoys a certain independence, and presides over the conscious 

 life of the segment of the body which corresponds with it ? In 

 this case, there would be a kind of regional division of conscious 

 nervous labour, and the cerebroidal or superoesophagian ganglion 

 would scarcely have any advantage over the others but that of 

 presiding over vision, and of being in consequence intrusted with 

 the guidance of the whole cohort drawn up behind it. l A cele- 

 brated experiment of Duges seems at first to solve the question 

 affirmatively : " I rapidly cut off," he says, " with scissors, the 

 protothorax or protodere of the Mantis rdigiosa ; the posterior 

 1 Dugks, Physiologic ComparSe, t. I. p. 343. 



