154 THE PROBLEM OF EVOLUTION 



function has not yet been ascertained. Some 

 years ago, Ribbert, a great pathologist, writing 

 in Virchow's Archiv, expressed the opinion 

 that an obliteration of the cavity of the 

 appendix, occurring during life, was a typical 

 instance of the process of involution. If this 

 were true, the appendix would seem to be 

 really a rudimentary organ. But in 1902 it 

 was shown by Dr. Joseph Koch that these 

 obliterations are to be regarded solely as conse- 

 quences of previous inflammation. (Observations 

 on chronic or recurrent perityphlitis based 

 upon two hundred operations, Archiv fur klin. 

 Chirurgie (Records of Clinical Surgery), vol. 

 Ixvii., 1902, Part n.) An exact proof of the 

 accuracy of this theory was given in 1904 

 by Professor L. Aschoff, in the Proceedings of 

 the German Pathological Society (p. 246, etc.), 

 in an article on the topography of appendicitis. 

 Professor Rotter, of the Hedwigskrankenhaus 

 in Berlin, placed at his disposal for purposes of 

 investigation one hundred and three vermiform 

 appendices. The work already mentioned by 

 Dr. Koch, who was then assistant physician 

 at the same hospital, is based upon the same 

 materials. According to these specialists, the 

 vermiform appendix of the caecum closes up 

 only in consequence of morbid appearances. 

 Under normal conditions in a healthy person, 

 we may infer, judging from its gland tissue, 



