268 HISTOLOGY 



layer of fibers in the connective tissue which lies just beneath the base- 

 ment membrane. These perceptory cells are peculiar nerve elements 

 because of the small size of their cytoplasmic bodies, which are barely 

 large enough to hold the very small oval nucleus. 



Technic. Nitrate of silver by the rapid process and one good method 

 of paraffin sectioning is all that is needed to study the olfactory organs, 

 although the macerated section method is very applicable in this epithe- 

 lium, also. Where the epithelium is covered with a cuticle, as in the 

 insects, the cuticle is almost always very thin and forms no noticeable 

 obstacle to the cutting. 



LITERATURE 



GRABERG, J. "Zur Kenntniss des cellulosen Baues der Geschmacksknospen beira 



Menchen," Anal. Hefte, Band XII, 1899, S. 337. 



NAGEL, WILIBALD. "Die niederen Sinne der Insecten," Tubingen, 1892. 

 VOMRATH, O. Articles on the Nerve-Ending in several recent volumes of Zeits. f. Wiss. 



Zool. 



