266 Journal of Comparative Neurology. 



the exact courses of the several nerve components through the 

 ganglionic complexes. Even Cole, whose researches on the 

 nerves of fishes are in many respects the most valuable which 

 we have had since Stannius, was only partially successful in his 

 analysis of these complexes. 



In the course of the final revision for the press of my pre- 

 vious contribution upon the peripheral nervous system of Men- 

 idia I received Cole's memoir on the nerves and lateral line 

 system of the cod, to which reference has just been made. I 

 was pleased to find a close agreement between his conclusions 

 and my own in most important respects. There were, however, 

 some points of difference, not only in the theoretical deductions 

 to which we were led by our facts, but in the basal facts them- 

 selves — differences which could be explained only on the as- 

 sumption either of erronious observation on the part of Cole or 

 myself or of differences in the structure of the two fishes under 

 consideration which would be most unexpected in view of their 

 rather close relationship. 



These discrepancies are in some cases important, not as 

 mere matters of anatomical detail, but because of their broader 

 application to the theories of nerve components, upon which I 

 was at that time especially engaged. I therefore determined to 

 examine some points in the structure of the peripheral nerves 

 of the genus Gadus myself. 



The differences between Cole's results and my own are 

 almost altogether such as can be cleared up only by the micro- 

 scopical analysis of the nerve roots ; I therefore employed in 

 the main the same methods as those used in the research upon 

 Menidia already referred to; viz., the preparation of serial sec- 

 tions of small fish, hardened entire in Flemming's fluid and 

 stained by the Weigert method. The young specimens of 

 Gadus morrhua, about 7 cm. long which were sectioned in this 

 way were dredged for me in Vineyard Sound by Mr. Vinal 

 Edwards of the Woods Hole Station of the U. S. Fish Com- 

 mission during the summer of 1 898 ; the sections I prepared, 

 tivith the assistance of my pupil. Miss Laura B. Moore, in the 

 Zoological Laboratory of Denison University ; and the micro- 



