Sorensen, Study of Epiphysis and Roof of Diencephalon. 29 



later stages of its development and shows nothing peculiar be- 

 yond this. 



(4) In the Anura, on the other hand, it becomes pear- 

 shaped and grows forward. By farther development the vesic- 

 ular tip is constricted off and comes to lie outside of the brain 

 and later outside of the cranium ; while the stalk-like end cov- 

 ered by the meninges persists within the skull cavity as the 

 epiphysis. 



(5) In adult animals the part of the epiphysis constricted 

 off lies deeply imbedded in the cutis vera under the epidermis 

 as Stieda's gland, becomes surrounded by a peculiar connective- 

 tissue covering and shows a retrogressive metamorphosis in that 

 it degenerates into fat. 



(6) The very thin filament which in many cases joins the 

 portion of the epiphysis which was constricted off with the spot 

 lying between the ossa fronto-parietalia and was considered by 

 Gotte as the epiphysial stalk is nothing but a subcutaneous 

 nerve, a filament of the Ramus supra-maxillaris N. trigemini. 



(7) This filament generally runs in the manner mentioned. 

 Occasionally, however, it comes from the region of the eye and 

 ascends along the inner surface of the skin opposite to the ex- 

 tra-cranial part of the epiphysis ; and sometimes it is wanting 

 altogether. 



(8) In the cases in which it ascends it ends in the con- 

 nective-tissue capsule, never in the portion of the epiphysis in 

 question. 



(9) From the structure of the epiphysis of adults it can be 

 determined with certainty whether a portion has been constricted 

 off or not; in the former case it bends forward and ends in a 

 point, in the latter it is fungiform. 



(10) In Rana esculenta, Rana temporaria, Alytes obstet- 

 ricans, Bombinator igneus, Bufo cinereus, we find the extra- 

 cranial portion of the epiphysis present, while it is entirely want- 

 ing in the adult of Hyla arborea. The tip of the epiphysis 

 running forward shows, however, nat in this animal a portion 

 is constricted off in the embryological condition. 



