Bawden, Nose and Jacobsons Organ. 131 



The frontals appear to be larger than the parietals which they 

 partially overlap; the parietals lying just in front of the auditory 

 capsule are not represented in the figures. 



The nasals (Figs. 6-15, n) are wedged in between the nasal 

 process of the premaxillary in front, and the ectethmoid behind, 

 meeting the maxillary at different points laterally. The nasal, 

 like the frontal bones, is closely applied to the cartilaginous 

 plate and olfactory capsule, but does not graft itself upon the 

 cartilage so as to ossify it. A general knowledge of the rela- 

 tions of the investment in the different types of Amphibia under 

 discussion may be gained by a comparison of the various draw- 

 ings of models and sections ; especially see Plates X-XII. 



III. Naso- lachrymal and Glands. 



The general relations of the naso-lachrymal in Amphibia, to 

 the apparatus which corresponds to it in higher vertebrates has 

 been amply discussed by Born (No. 4.) We here briefly de- 

 scribe it as we have found it in different types, and from draw- 

 ings of our own. 



The Naso-lacJirymal duct conducts the lachrymal secretion 

 from the conjunctival sac of the eye into the nasal cavity. This 

 duct is found in some cases as a shallow furrow which runs 

 downward to the upper margin of the mouth. This stage is the 

 permanent condition in many Selachians, and is found in the 

 embryonic stages of some higher types. ( See European sala- 

 mander, below.) 



The naso-lachrymal duct in Salamandra atra, European 

 salamander, at first where it has its origin in connection with 

 the eye, (within the inner lower lid of the eye) passes as a naso- 

 lachrymal sinus for most of the way until it comes into the vicin- 

 ity of the olfactory cavity where it dips beneath the surface pas- 

 sing for a short distance as a closed duct. See model, Fig. 1, 

 Plate XI, ;//, or, op, ey; dorsal view, as also of Amblystoma, 

 Fig. 3, Plate XII. This duct then suddenly drops ventrally 

 ending in a ventro-lateral diverticle of the cavity at or. This is 

 seen in Fig. 1, nl, Plate VI and Fig. 2, Plate XI, or, and Fig. 1, 

 Plate XI, or. 



