A Oonfribiitioii to tlip Anafoiny of Siren lacertinft. ß87 



logue of Jacobson's organ of the Reptilia, and that wo have here 

 several stages in its phylogenetic development, seem to me highly 

 probable, I hope soon to be able to present the results of farther 

 researches upon this liüe, which may add to the knowledge of Jacob- 

 son's organ, it being also not unlikely that by such investigation added 

 light may be thrown upon the phylogeny of the Amphibians. 



D. Intermaxillary Glands (fig. 12 A, B, C Gl), 



Intermaxillary space. Siren possesses a true intermaxilhiry 

 space which lies between the two ethmoids, the internasal septum 

 forming its floor, and the anterior processes of the frontals its roof. 

 It forms a continuation of the brain-cavity and may be said to com- 

 mence at the point where the olfactory nerves enter the nasal capsul«\ 



The cavity is flattened cone-shaped, thus being always oval in 

 cross-section. Anteriorly the cavity is demonstrable beyond, the acces- 

 sory nasal cavities, the section given at C (fig. 12) being near its 

 anterior limit. The cavity is not as large as the space between the 

 bones would permit, but a considerable portion of the space is filled 

 by loose connective tissue, in addition to which there are, at the 

 anterior end, several layers of pigment cells, lining the cavity. The 

 histological conditions thus give the impression that a secondary filling- 

 up of a formerly larger cavity has taken place. 



Glands. In the posterior part of the nasal region, at the point 

 where the olfactory nerve enters the capsule, there appear several 

 scattered glands, which lie between the nasal mucous membrane and 

 the ethmoid bonq, partially surrounding the deep ophthalmic nerve. 

 Anteriorly they increase in number, and as the ethmoid bones gradu- 

 ally diminish in size, the glandular masses of the two sides approach 

 one another. At the point shown in C (fig. 12), the glands reach the 

 intermaxillary space, and by means of a few scattered glands found 

 in the space itself, form a nearly continuous mass from one side across 

 to the other. 



More anterior to this place, the intermaxillary space is obliterated 

 and the glands are again confined to the sides, extending how^ever 

 only a short distance beyond the point where the two sides connect. 

 Histologically the lateral glandular masses and the scattered glands 

 of the intermaxillary space are identical, appearing like the true inter- 

 maxillary glands of the terrestrical salamanders and bearing no resem- 

 blance to the glands of Bowman. 



They are plainly intermaxillary glands which have wandered out 



