20 Effie A. Read 



and a fusiform cell. The cj'lindrical cells reached the free surface and 

 were connected, according to Ecker, by the central prolongations with 

 the olfactory fibrils. These he called the true olfactory cells. The 

 fusiform cells, replacement cells, situated at the base of the epithelium 

 never reached the free surface. These replacement cells were simply 

 stages in the development of the olfactory cells. Thus there was, 

 according to Ecker, only one kind of cell, hut in difEerent developmental 

 stages. 



Scliultzc, 1856, worked on man, mammals, birds and amphibia. He 

 found three kinds of cells, olfactory cells, epithelial cells and stellate 

 cells. The epithelial cell was long, with a prismatic ])eripheral end. 

 The central end was a short process and was connected with neighboring 

 epithelial cells through side processes. These cells were pigmented but 

 not ciliated. Between the epithelial cells he found cells of a peculiar 

 chemical reaction. The cell bodies were round and had two processes, 

 one reaching the free surface of the epithelial cells and the other passing 

 to the connective tissue. This central process was the finer and could 

 be recognized by the enlargements. The peripheral process was wide, 

 at first, but tapered quickly and was then the same width to the surface. 

 It bore at the end six to ten long brush-like hairs which were free in 

 the air current of the nose. He describes each epithelial cell as sur- 

 rounded by at least four to six of these hair cells. 



In a comparison of these peculiar fiber cells of the olfactory region with 

 other known cell forms, he first emphasizes the fact that in no other 

 epithelial layer, either in the nose outward from the olfactory region, 

 or back in the air tubes, is a trace of sucli varicose fiber cell found. 

 The stellate cells, which lie under and between the surface cells, do not 

 have the form, length or nature of the other cells of the olfactory region. 



Pie believes the nerve cells of the retina to be the most favorable for 

 comparison with these cells. By a comparison of these with the bipolar 

 cells and by a comparison of the chemical reaction of the two cells, it is 

 highly probable, according to Schultze, that these cells are also ganglion 

 cells. He adds that comparative researches have made it as good as 

 certain that the varicose fiber cells of the olfactory region are nerve 

 cells. It, however, lacks proof of a direct connection with the fiber of 

 the olfactory nerve. He concludes by saying that it is highly probable 

 that the varicose fiber cells are the peripheral ends of the olfactory 

 nerves. It is to these cells, and not to the epithelial cells, as Ecker 

 thought, that the name olfactory cell should be given. These cilia- 



