592 THE PHYSIOLOGY OF REPRODUCTION 



leading to a complete disintegration of the secretory cells of the 

 mammary gland. 1 According to this theory the colostrum corpuscles 

 were the detached epithelial cells. In opposition to this theory, it 

 has been pointed out that there is no evidence of the extensive cell 

 multiplication, such as would be required in order to supply the large 

 number of cells which, according to this hypothesis, would necessarily 

 become detached. Heidenhain 2 has shown that if this theory is 

 correct, the cells of the gland must be completely renewed as often 

 as five times in one day in order to provide the solid constituents of 

 the secretion. 



The second of the above-mentioned theories receives considerable 

 support from the circumstance that it has the analogy of the great 

 majority of secretory glands. 3 Moreover, the results of Bertkau's 4 

 investigation point strongly to the conclusion that any appearances of 



FIG. 165. Section through an alveolus with fat drops in cells. (From 

 Sharpey Schafer, after von Ebner.) 



e, Cells of alveolus ; /, cells of basement membrane (m) ; i, connective tissue. 



disintegration which the secretory cells possess are due to imperfect 

 fixation. This author states that he found no necrobiosis of any 

 kind in these cells, and he believes that milk formation is a purely 

 secretory process. This view is now widely accepted and the colostrum 

 corpuscl.es are regarded as of the nature of wandering leucocytes. 



The third theory was first suggested by Langer, and has since 

 been adopted, with various slight modifications, by Heidenhain, 5 

 Steinhaus, 6 and Brouha 7 and others. According to their view the 



1 Virchow, Die Cellular- Pathologie, Berlin, 1871. 



2 Heidenhain, "Die Milchabsonderung," Hermanns ffandbuck der Physiologic, 

 vol. iv., 1883. 



3 Sharpey Schafer, loc. cit. 



4 Bertkau, " Ein Beitrag zur Anatomic und Physiologic der Milchdriise," 

 Anat. Anz., vol. xxx., 1907. 



5 Heidenhain, he. cit. 



6 Steinhaus, "Die Morphologic der Milchabsonderung," Arch. f. Anat. u. 

 Phys., Phys. Abth., Suppl., 1892. 



7 Brouha's paper (loc. cit.) contains a full account of the literature. 



