EVOLUTION AND SIGNIFICANCE OF CEREBRAL CORTEX 303 



the enlargement of the centers for taste, 1 and these reflex centers 

 x are found to be very complex. The enormous increase in the 

 mass and complexity of arrangement of the gustatory neurons in 

 Carpiodes does not imply any higher organization from the 

 standpoint of range of behavior (see p. 19) than in Hyodon. 

 The apparatus is more efficient as a means of sorting out food 

 particles from mud, but we do not rank this form of activity 

 very high in our scale of behavior. 



medulla 

 oblongata-' 



Fig. 136. Illustrations of the brains of two rather closely allied species 

 of fishes showing very different development of the reflex centers of the 

 medulla oblongata: (1) Hyodon tergisus, the moon-eye, (2) Carpiodes tumi- 

 dus, a carp-like species. (After C. L. Herrick.) 



In general, in the execution of a complicated reflex many inter- 

 connected nerve-centers are so arranged that they discharge 

 into a common final path or an integrated series of such coordi- 

 nated paths. The movements involved in the act, if performed 

 at all, must follow in a definite sequence which is structurally 



1 For an analysis of this gustatory apparatus in fishes, see HERRICK, C. 

 JTJDSON. The Central Gustatory Paths in the Brains of Bony Fishes, 

 Jour. Comp. Neurol., vol. xv, 1905, pp. 375-456. 



