400 URBAN PKITCHARD. 



rounded by protoplasm and having prolongations upwards 

 and downwards, the former passing between the cylindrical 

 cells, and the latter between the nuclei of the lower layer, 

 — these middle cells he termed Fadenzellen. He admitted 

 that he was unable to trace the exact origin of the cilia 

 which project from' the epithelial layer. 



Odenius, Kolliker, and Max Schultze himself, in his later 

 researches, found similar structures in the higher animals ; 

 and although they differed somewhat in details, yet they 

 came essentially to the same results. 



Hasse, in his earlier researches on the bird, found himself 

 unable to corroborate the statements of Max Schultze, and he 

 described the nerve-epithelium as consisting of two alternat- 

 ing forms of almost cylindrical epithelial cells. The one 

 bearing the cilium he very aptly terms the thorn cell, and 

 the other the isolating cell. 



The thorn cells he describes as being fusiform, with the 

 thorn projecting from its upper part ; the isolating cells as 

 enlarged at their base, which contains nuclei and rest on the 

 tunica propria, the upper part of the cells being narrow, and 

 passing between the thorn cells so as to separate them. 



E-iidinger, in his description of this structure in ^Strieker's 

 Histology,' somewhat reverses Hasse's statement, and depict 

 it as consisting of fusiform ciliated cells alternating with 

 triangular ones, with their bases turned upwards instead of 

 downwards. At the same time he states that he has been 

 unable to discover the deep layer of nuclei described by Max 

 Schultze. 



Ebner, in endeavouring to reconcile the opposing state- 

 ments of Max Schultze and Hasse, came to a conclusion which 

 differed from each. He considers that this nerve epithelium 

 consists of two parts — a superficial layer of cylindrical 

 ciliated cells with a cuticular border above, and rounded off 

 below, and layers of fusiform cells made up of a nucleus and 

 two fine prolongations, the upper one passing between the 

 cylindrical cells as far as the cuticular border. The nuclei 

 of this second set of cells correspond to the deep layer of Max 

 Schultze. 



Lastly, Meyer, in his elaborate work on the membranous 

 labyrinth, just published, arrives at very different results. 

 He describes a deep layer of nuclei, as Max Schultze, and 

 above this a layer of cylindrical cells, with cilia projecting 

 from their upper free ends, and abruptly tapering to a nerve 

 filament below. 



My observations have led me to conclusions which, 

 although they are essentially different from those of the 



