74 



Dr. J. Homans. The Relation of the 



[Oct. 1, 



starvation, and duct ligation, the formation of new islets from acini. 

 Karakaschiff (1904-1906), in a study of diabetes in man, finds that islets are 

 without function except to form acini. Herxheimer (1906), in a similar 

 study, concludes that islets are made from acini as a regenerative process. 

 Vincent and Thompson (1907) agree with Dale. Fischer (1912) believes that 

 the islet cells are able rapidly to change in function and appearance. 



From the point of view of independence of function, the opinions of those who, 

 following the lead of Mering and Minkowski, have endeavoured to discover which 

 part of the pancreas is concerned with the sugar function are more in agreement. 

 Thus Schultze (1900), Ssobolew (1902), Sauerbeck (1904), Tschassownikow 

 (1905), Tiberti (1909), and Laguesse (1911) substantially agree that duct ligation 

 does not produce diabetes. Of these, all but Sauerbeck find that islet tissue is 

 not destroyed in the process, and this conclusion, taken into consideration with 

 the occasional finding by Opie (1901) and others of extensive islet disease in 

 human diabetes, furnishes a strong argument in favour of the functional 

 independence of this tissue. Partial extirpations and pancreatic grafts by 

 Laguesse (1902), Kyrle (1908), Tiberti and Franchetti (1909) have led to 

 similar conclusions. It must be admitted, however, that except for Ssobolew 

 (1902) no one has been able to see as a result of stimulation with carbo- 

 hydrates or phloridzin any changes in the islet cell indicating stages of 

 functional activity [Tiberti (1909), Frugini and Stradiotti (1909)]. 



The supporters of the view that islets are unchangeable anatomic structures 

 bring evidence from a number of sources. Embryologic investigations by 

 Pearce (1903), Krister (1904), Helly (1905), and Weichselbaum and Kyrle 

 (1909) point to the origin of islets in early foetal life from primitive duct 

 tissue and to their subsequent anatomic independence. None of these 

 investigators have been able to confirm the observations of Laguesse (1895-6) 

 in regard to the disappearance of his " primary " islets and the substitution of 

 " secondary " islets from acinous tissue. 



Other investigators, by methods similar to those employed by Lewaschew, 

 Minkowski and Dale, have come to conclusions diametrically opposite to theirs, 

 a fact which suggests that the matter is, to a great extent, one of interpreta- 

 tion of the histologic appearances and of microscopic technique. Thus 

 Diamare (1899) finds that the islets contain two kinds of specific granules, 

 and have an important sugar function. Opie (1900) finds no increase in the 

 number of islets after prolonged stimulation with pilocarpin. Ssobolew 

 (1902) holds the islets to be independent structurally as well as functionally. 

 He sees specific granules in the islet cell. Dewitt (1906) finds a great 

 variation in the normal number of islets, but no increase or change resulting 

 from starvation, feeding, and so on. Lane (1907) shows that there are two 



