36 AMERICAN MIDLAND N'ATURALIST 



author of all papers which a student under him defended. Accord- 

 ing to this, Retzius must be credited with the genus. This law 

 was repealed in Lund in 1852." — Simpson, Charles Torrey, in 

 Synopsis of the Naiades, or Pearly Fresh-water Mussels. Proc. U. S. 

 Nat. Mus. XXII.: 679, footnote. [1900]. 



3. "The real author of the 'Dissert, hist. nat. nova test, 

 genera' was A. J. Retzius, the respondent, Philipsson merely took 

 his degree for undergoing examination on the subject after the 

 custom of those times, especially in Sweden." — B. Woodward, 

 (British Museum) in letter to Librarian. Upper Iowa University, 

 7 May, 191 2. 



4. "The genus Unio was defined in a thesis written by 

 Retzius the praeses and Philipsson got his degree for defending 

 it in public as was the practice of the time. Frequently the thesis 

 would be apportioned out to two or more students and frequently 

 one half of a word will appear at the end of one respondent's part 

 and the rest of it in the next man's and the two separated by the 

 new title page and dedication to parents. 



" Occasionally only did a brilliant student write his own thesis 

 and then there usually appears on the title page "auctor respon- 

 dens" — or some such phrase. 



"That this was the custom, you will find set forth in Lin- 

 naeus' 'Bbl. Bot.' 1736, p. 52. 



" There is not the slightest doubt as to Retzius being the 

 author of the thesis in question." — ^B. Woodward (British Museum), 

 in letter of 10 June, 1912. 



5. " As to the authority for Unio, it is well established that 

 it is due^to'^Retzius. If his name does not appear as author on 

 the printed thesis, neither does Philipsson 's. The paper is merely 

 said to be 'presented' (defert) by Philipsson. When a paper was 

 presented by its author, 'auctor' was used. These theses were 

 presented and defended, (and still are) before the examining 

 board of the University without reference to authorship. Phil- 

 ipsson's thesis was not 'published.' It was printed by the Berling 

 Press at Lund, but bears no publisher's name. So, as he claims 

 no authorship, and there is no publisher, and we know from con- 

 temporary usage that Retzius did write it, it seems to me to be 

 stretching a technicality to the breaking point to say that we 

 must credit the genus to Philipsson. I shall never do it, and so 

 advised Simpson."- — Dr. W. H. Dall, in Letter of 13 Feb., 191 2. 



