138 Journal of Comparative Neurology 



glomerule. See Current Views of the Structure of Olfactory- 

 Organs and Taste-bulbs, Journ. Compar. Neurol., Ill, Sept, 



i8 9 3- 



Previous investigators have discovered a difference in the 

 nerve end-filaments as found in olfactory epithelium, as com- 

 pared with the epidermal, optic, auditory and gustatory. They 

 have claimed that in the former case the nerve filaments enter 

 into immediate connection with the cells. Recently some auth- 

 ors have endeavored to show that filaments enter the cells of 

 Corti in the ear, and the cells of the corium of the skin. But 

 these investigators (notably Ayers and Pfitzner) have not made 

 good their claims to the satisfaction of many, so that the olfac- 

 tory epithelium still appears to hold its peculiar position in this 

 respect. 



Our own studies of the olfactory epithelium of trout, sala- 

 mander and frog, confirm the general belief that there are two 

 kinds of cells, the smaller sensory type, and the larger monliform 

 supporting type. (Fig. 6, Plate VII ; Fig. 2, 4, 5, 7, Frog, a, 

 Plate VII). The smaller cells (Trout) are probably as Max 

 Schultze calls them, "the true olfactory cells. " They consist of 

 a nucleus and two long processes, the one ending upon the sur- 

 face of the mucous membrane and ciliated, and the other pass- 

 ing back through the ganglionic nutritive layer and terminating 

 in connection with a filament from the nerve-bundle. The larger 

 supportive cells (Figs. 2-7, b, Plate VII) are also ciliated upon 

 their free ends and as indicated by the term, moniliform, seem to 

 consist of several cells superimposed upon one another, forming 

 a bi- or tri-nucleated rod, as it were. That these are really 

 several cells successively impinged one upon another, and not, 

 as some seem to think, poly-nucleated single cells seems to be 

 quite clearly demonstrated by a careful drawing of a portion of 

 the olfactory epithelium in Amblystoma piinctatum. See Fig. 2, 

 a, b, Plate VII. 



A peculiarity of the olfactory cavity of Amblystoma is the 

 presence and marked development of numerous crypts formed 

 by the deep foldsinthe olfactory epithelium (Fig. 1, Plate VII, 

 Cty.) Between these and lying about and among them are the 



