72 'Journal of Comparative Neurology and Psychology. 



ing fibers. Some of them may pass over into the opposite tractus 

 bulbo-tectahs (lemniscus), but it is not possible to be certain on 

 account of the confusion in the ventral commissure of the internal 

 arcuate fibers from the lateral vagal lobule with those from the 

 tuberculum acusticum. This connection through the ventral 

 commissure puts the lateral vagal lobule into connection with the 

 long conduction paths of the somatic system, and thus directly 

 connects the primary center for cutaneous taste buds and the ven- 

 tral cornua of the spinal cord, from which the muscles of the fins 

 and body are innervated. These relations are shown diagram- 

 matically in Fig. 2. 



The representatives of the Ostariophysi which I have studied 

 (Ameiurus, Cyprinius, Catostomus, etc.) agree in possessing a 

 distinct center (the facial lobe) for all of the fibers from cutaneous 

 taste buds, the secondary connections of this center being partly 

 with visceral motor and partly with somatic motor centers via the 

 funicular nuclei. The fact that Gadus accomplishes a somewhat 

 similar result by the different and more direct method of separating 

 at the start the facialis root fibers into those for visceral and soma- 

 tic centers is another illustration of the distinctness of the Ostario- 

 physi from other teleostean fishes. 



The end result is similar in the case of the cod and the catfish. 

 Peripheral areas of skin may receive both tactile and gustatory 

 stimulation simultaneously. The fish reacts to the composite 

 stimulus by a single movement of the body adapted to reach and 

 seize the food object. The tactile path in both cases leads to the 

 funicular nuclei, and thence to the somatic muscles. The somatic 

 gustatory path in the catfish leads to the tactile correlation center 

 (funicular nuclei), whence it reaches the somatic muscles by the 

 same tracts as the tactile. In the cod the somatic gustatory path 

 passes directly from the primary center to the somatic motor cen- 

 ters in the ventral cornu without interruption in the tactile centers. 



In searching for the explanation of this difference two lines of 

 inquiry are at once suggested. First, are there any mechanical 

 necessities of cerebral structure sufficient to account for them; and, 

 second, do the habitual modes of reaction to external stimuli, 

 I. ^., the habits of the animals, suggest an explanation. I believe 

 that both of these factors have operated. 



In the first place, why do the somatic gustatory nerves of the 

 cod end in a specialized part of the vagal lobe and those of Ameiu- 



