Herrick, Brain of the Codfish. ']'] 



The dorsal cornua at the levels of the fourth and fifth spinals 

 are reduced to the meager dimensions commonly seen in teleosts. 

 The cross-section of the spinal cord at this level is almost com- 

 pletely filled with very large medullated fibers, showing that long 

 conduction paths are here more important than short reflex con- 

 nections. The dorso-lateral fasciculi, in particular, are large and 

 heavily medullated. In this respect the cod resembles the eel and 

 other fishes with highly developed body musculature, in striking 

 contrast with the sluggish catfish. Even the cyprinoids, like the 

 carp and the gold-fish, have far smaller longitudinal spinal tracts. 

 At the cephalic end of the spinal cord (third spinals to vagal lobes) 

 the same compact formation of the long tracts is evident as farther 

 caudad, save in the dorsal cornu and funicular nucleus region. 

 The dorsal funiculi disappear in the most caudal part of these 

 nuclei and the dorso-lateral fasciculus sends large tracts into them 

 for their entire extent, suffering corresponding reduction in size 

 cephalad. A considerable proportion of this fasciculus, however, 

 passes farther cephalad to terminate in the oblongata. The ventro- 

 lateral fasciculi also decrease greatly in size in the funicular 

 nucleus region, or more properly expressed, they increase as they 

 pass caudad under the funicular nuclei by accretions from this 

 region. The lateral fasciculi (tracts midway between dorsal and 

 ventral funiculi) also suffer considerable diminution in this region; 

 but some strong bundles of these fibers pass directly cephalad 

 from the spinal cord into the brain as the tractus spino-tectalis, 

 to be greatly augmented in the region of the tuberculum acusti- 

 cum by the tractus bulbo-tectalis. 



We conclude, then, that in Gadus the region of the funicular and 

 commissural nuclei is-, as in other types of fishes, a correlation 

 center for all tactile impressions from the skin and their motor 

 responses. The pectoral and pelvic fins of the gadoids are particu- 

 larly delicate tactile organs and the dorsal cornua of the anterior 

 end of the spinal cord have been enlarged and intimately related 

 to the funicular nuclei and somatic commissural nucleus to serve 

 these sense organs. This process has been carried to a much 

 greater extreme in the gurnards (Trigla, Prionotus, etc.). But 

 the taste buds located on these fins in the gadoids, as we have seen 

 above, are not centrally connected with this tactile correlation 

 center, as they are in the siluroids and cyprinoids, but effect an 



