Bawden, Nose and Jacobson's Organ. 135 



folds which represents the eyelids, a rod-like thickening of the 

 epidermis which seems to be distinct from its mesodermic sur- 

 roundings, and to resemble the naso-lachrymal duct ; ending, as 

 it does, in the lower eyelid, where as usual it splits in two, the 

 outer branch not quite reaching the epidermis while the inner 

 one does. 



Glands. — Bowman's glands (in Gymnophiond) are grouped 

 on the dorsal transition area of the olfactory organ where it bulges 

 out to form what has been homologized with the Jacobson's 

 diverticle. Burckhardt further distinguishes in this group what 

 he calls Jacobson's gland which forms a richly branched mesh- 

 work at the base of the olfactory sac where it opens into the 

 external nares, the structure being the same as the dorsal nasal 

 glands. 



These glands as seen in Urodela are well exhibited in Fig. 

 4, gla, Plate VI, Dicmyctylus vuidescens, where they are seen in 

 connection with the diverticle j'd, which is characteristic of this 

 group. See also fig. 3, Plate VI, gla, Ambly stoma punctatum. 

 They are further shown in the different models lying, as they 

 do, in their different relative positions in the different types. 



In Salamandra atra they are seen in Fig. 1, Plate XI, gla, 

 dorsal view of cavity, just a glimpse of them being obtained 

 in this figure as they are hidden by the overarching projection 

 of the premaxillary. In fig. 2, Plate XI, gla, which represents 

 a ventral view of the same they are seen lying on the inner ven- 

 tral aspect of the cavity at about the center of its longitudinal 

 axis. 



In Amblystoma punctatum they lie scattered more promis- 

 cuously along almost the whole ventral median aspect of the 

 cavity as seen modelled at gla, Fig. 4, Plate XII. They are 

 represented in the model by ridges or furrows. See also gla, 

 fig. 1, Plate VII, also gla, Fig. 1, Plate IX and figs. 3-5, 

 Plate V. 



Born distinguishes in Anura four different groups of glands: 

 two opening into the nasal cavity and two emptying into the 

 mouth and throat respectively. The two latter, the intermax- 

 illary and choanal, on account of their position, are not shown 



