134 Journal of Comparative Neurology 



it ends in two grooves which separately open upon the free mar- 

 gin of the inner half of the lid. In the larvae they end on the 

 inner side, while in the adult, as a rule, they end nearer the 

 outer side of the lid. 



"If in an adult frog you expose the three nasal cavities " says 

 Born (No. 4), "it is easily possible to see in the section of the 

 lateral sac a fine tubular connection " which may be recognized 

 as the naso-lachrymal duct. How this tube closes up from its 

 original position as a mere groove is not yet clear, but it is al- 

 ways so seen. The canal never appears in the adult as a groove 

 but always as a closed cavity. It appears, on section, in con- 

 nection with a black band, in the larvae, which in Rana esculenta 

 stretches from the eye to the nose. The canal passes out 

 through the upper nasal glands, up (Fig. 3, Plate VIII), is widest 

 nearest the nasal end and narrows on approaching the lid. This is 

 nicely shown in Bufo lentigcnosus, Fig. 1, Plate XII, up, or, 

 nl. Its epithelium is, in general, of the same character as that 

 of the lateral cul-de-sac. 



The general relations of the naso-lachrymal in the adult 

 Rana vircscens were so nearly identical with those in Hyla versi- 

 color, that the conditions as found in the latter only were mod- 

 elled. It is essentially such as described by Born in his work 

 entitled " Ueber die Nasenhohlen und den Thranenasengang 

 der Amphibien" (No. 4). These relations are modelled in Figs. 

 3, 4, Plate XI, at nl, or, bi, 7ip, etc. Figs. 3-6, Plate VIII, nl 

 and or are four camera-drawings which illustrate the methods of 

 origin of the duct in both these types. 



In Bufo lentigcnosus modelled in Figs. 1 and 2, Plate 

 XII, we find the naso-lachrymal originating as in all Anura from 

 its own special diverticle, Ic, upon the external aspect just be- 

 hind the external nares, cxll. In spite of the marked differ- 

 ence in the general configuration of the nasal cavity in this type 

 as compared with other adult Anura, it is not difficult to homol- 

 ogize it with other types in this respect. See nl, or, up, etc., 

 figs. 1, 2, Plate XII. 



Born (No. 1 8) further has shown in the lizard and chick, at 

 the base of the groove separating the nasal passage from the 



