CHAPTER XL 



GLANDS AND THE GENERAL PHYSIOLOGY OF 

 SECRETION. 



HISTORICAL. 



The ancients had practically no knowledge of secretion. 

 They thought that the phlegm from the nose was a dis- 

 charge from the brain. Their other views were not less 

 mistaken. This misconception lasted until 1660, when 

 Schneider's researches on the olfactory membrane proved 

 its falsity. About this time, too, a number of eminent an- 

 atomists appeared, whose researches on the structure of 

 glands materially cleared up the meaning of these organs. 

 The names of many of these noted anatomists are still re- 

 tained in connection with the terminology of glands. Thus, 

 Glisson (Capsule of Glisson in the liver), Stenson (Duct of 

 Stenson in the salivary glands), Peyer (Patches of Peyer in 

 the intestines), Brunner (Glands of Brunner in the duode- 

 num), and Malpighi (Malpighian corpuscles of kidneyj. 

 Our anatomical knowledge became finally fairly complete 

 when in 1830 Johann Mueller's large treatise on glands was 

 published. 



Thus far, all the work had been of an anatomical nature 

 and the physiological process of secretion remained for 

 some time longer entirely unknown. The view held was 

 that the blood capillaries actually communicated with the 

 ultimate tubules of the ducts of the gland, and that the 

 secretion was a kind of direct separation from the blood, in 

 which the corpuscles did not take part, because the smaller 

 tubules of the duct were too tiny to allow them to pass from 

 the blood. The correct view of the process of secretion, 

 however, soon followed the discovery of the cellular struc- 

 ture of animal tissues by Schwann, and the discovery of 



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