STUDIES FROM THE NEUROLOGICAL LABORA- 

 TORY OF DENISON UNIVERSITY. 



XI. The Cranial Nerves of Amblystoma punctatum. 

 With Plates XIX and XX. 



By C. Judson Herrick, 



Fellow in Neurology. 



Within recent years both Professor Osborn [5] and Mr. 

 Strong [8] have urged the necessity of fixing the homologies of 

 the cranial nerves by an exact determination of both the periph- 

 eral and the central connections of the individual rami. Both of 

 .these investigators have made important additions to our knowl- 

 edge of this subject and it was in the hope of adding furthur 

 details that the present study was undertaken. The peripheral 

 distribution of the several cranial nerves of the type chosen has 

 been determined with considerable minuteness. Circumstances, 

 however, having prevented the further study of the internal 

 courses, it has seemed best to present the results already 

 obtained in the hope that they will prove useful to others who 

 may be working along the same lines, as well as to the students 

 of comparative anatomy in general. 



The present paper is based upon the study of two series of 

 transections of the entire head of Amblystoma punctatum. The 

 specimens were old larvae 8 to 10 cm. in length, taken only a 

 few days before the metamorphosis. The heads were fixed in 

 chrom-acetic 24 hours, hardened in alcohol gradatim, cut consec- 

 utively (22.7 micra in thickness) after paraffine imbedding, and 

 double stained, in the one case with aqueous hematoxylin and 

 picro-carmine, in the other with aqueous hematoxylin and 

 acid fuchsin in 90 per cent, alcohol. On account of the diffi- 

 culty in getting good picro-carmine, the latter is the more relia- 

 ble method. If the specimens are properly hardened, it serves 



