CHARACTERS OF THE OLFACTORY REGION. 203 



through the whole thickness of the membrane, and these, 

 I think, may best be made in specimens of the membrane 

 which have been hardened in solutions of chloride of gold 

 whilst still adherent to the bones. The various structures 

 are thus retained in their normal position, and appear sharply 

 defined. In fine sections of a nasal septum thus prepared 

 from the Guinea-pig, we find that the osseous portion of 

 the septum is invested by periosteum, which is immediately 

 covered by a thick layer of numerous and closely arranged 

 glands (fig. 337). These glands, named the "glands of 



Fig. 338. 



Fig. 338. Section of the olfactory mucous membrane of the Frog, 

 a, Gland of Bowman; 6, its orifice; c, fasciculus of nerve fibrils which 

 run between the epithelial cells. 



Bowman " by Kb'lliker, are elongated tubes, which, according to 

 the species of animal, are sometimes simple and more flask- 

 shaped than tubular ; and at others are multiform, and charac- 

 terized by pullulations, and by the sinuous course of their 

 blind extremities. Hence it rarely occurs, as the adjoining 

 woodcuts show, that, in vertical sections of the membrane of 

 the higher animals, any simple gland can be followed through- 

 out its whole length ; in general, only transverse sections of the 

 several parts, at different heights, are seen. Better prepara- 

 tions are obtained from the lower animals. The glands contain 

 an epithelium, which at the fundus consists of large granular, 

 nearly spherical cells, which in some animals have yellowish 



