ANIMAL PHYSIOLOGY. 



or nucleated corpuscles, it may be remarked that, in the in- 

 stance of one of the salivary glands (the sub-maxillary) in 



Fig. 34. LOBULE OF LIVER OF Fig. 35. LOBULE OF PAROTID 

 OYSTER. GLAND OF EMBRYO LAMB five 



-inches long. 



the rabbit and the ox, branches of nerve have been traced 

 under the microscope to the individual corpuscles, and it has 

 been found that stimulation of the chorda tympani nerve 

 supplying the gland excites secretion, and that the corpuscles 

 of a gland so excited have a different appearance from those 

 of a gland which has been at rest, losing the sharply denned 

 transparent and slightly striated appearance which they 

 have when at rest, the contour lines becoming indistinct, 



and the substance altered, so as 

 to be capable of being stained 

 more uniformly with carmine 

 (Heidenhain and PMger). So 

 also the secreting cells of the 

 glands of the stomach have 

 been found to have a different 

 appearance during digestion from 

 what they have in an unfed 

 animal, but no appearance of 

 multiplication of the cells at 

 these times can be detected. It 

 therefore appears that the se- 



Fig. 36. SECRETING COR- 

 PUSCLES of sub -maxillary 

 gland of the ox with nerve- 

 fibres ending in them. After 

 Pfiiiger. 



creting cells act by undergoing, under nervous stimulation, a 



