706 A. S. WARTHIN 



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of the whole is impossible. Only the actual achievements that have ad- 

 vanced our knowledge of pancreatic function and disease can be touched 

 upon. 



The older experiments of ligation or blocking with foreign material 

 of the pancreatic ducts were concerned chiefly with the changes produced 

 in intestinal digestion. Atrophy of the acinous portion without diabetes 

 was noted; but the state of the islands under such conditions was first 

 observed by Vassale (1891), who found them intact. His observations 

 were confirmed by Schultze (1900), Ssobolew (1901), Sauerbeck (1904), 

 De Witt (1906), Visentini (1908), Tiberti (1908), MacCallum (1909), 

 Kirkbride (1912), and Kamimura (1917). These investigators all noted 

 atrophy of the acini with preservation of the islands, and absence of per- 

 manent glycosuria after ligation of the ducts. MacCallum varied the liga- 

 tion experiment by separating the caudal portion of the gland and ligat- 

 ing the duct draining this area. A mild transient glycosuria followed. 

 Seven months later the atrophied portion was removed and examined 

 microscopically. It appeared to consist almost entirely of ducts and nests 

 of cells that he regarded as islets, but was not absolutely sure of their 

 identity. Kirkbride repeated this experiment with the same results, and 

 through the use of Lane's differential staining method for islet and acinar 

 cells (Bensley's neutral gentian) was convinced that the remaining paren- 

 chymatous tissue was made up of islet cells. On the other hand, Minkow- 

 ski (1900), Pende (1905), Lombroso (1905-1910), Zunz and Mayer 

 (1906) and Pratt (1910) found changes in both islands and acini. The 

 injection of oil into the ducts led to necrosis of both islands and acini. 

 Kamimura's research is the last important one in this line (1917). He 

 found that ligation of the pancreatic duct of the rabbit led constantly 

 to a complete atrophy of the parenchyma, while the islands of Langer- 

 hans were spared. The animals remained in good condition. The pro- 

 duction of an adrenal or hepatogenous hyperglycemia through injection of 

 adrenalin or diuretin, or through intravenous injection of grape-sugar, 

 produced the same variations in the blood-sugar as in normal animals. 

 Kamimura concludes that the intact islands remaining after ligation- 

 atrophy furnish the inner secretion of the organ which stabilizes the 

 carbohydrate metabolism of the animal. In another research he found that 

 injections of cytolytic sera obtained from islet tissue produced no gly- 

 cosuria. 



Island-theory of Internal Secretion. The island-theory was independ- 

 ently suggested by Laguesse (1893) ; he considered the cells of the islets 

 as possessing an internal secretion of importance in the carbohydrate me- 

 tabolism, while the acinar parenchyma secreted the external digestive 

 juice. He advanced a "balancement" theory of a progressive cyclic trans- 

 formation of acini into islands and the reverse for the complete production 

 of both secretions, basing this view upon apparent morphological transi- 



