HISTORY 29 



nests, partially devoured leaves, etc., the work of both larvae and 

 adults, the frass or excrements often of great importance, pupal 

 stages, adults of both sexes, and the parasitic and predacious 

 enemies also in all stages of development. Dr. Hagen's influence 

 upon the formation of such biological collections has been very 

 great; few were in existence at the time when, almost unaided, he 

 created that at Cambridge, and the care and elaborateness with 

 which the whole is labelled makes it not only a worthy model, but 

 most truly a monument to persistent and well directed industry. His 

 lectures, given at rare intervals to advanced students, contained 

 much genuine and exact knowledge, and his many acts of kindness 

 and words of wise counsel will not soon be forgotten by those who 

 enjoyed the facilities of the department under his charge." ^ 



Among Hagen's assistants and preparators, three are worthy of 

 mention, because they either gave him valuable aid in his curatorial 

 labors or actively increased the collections: Jacob Boll (1828-80), a 

 well-known Swiss naturalist, made important collections of insects 

 and other animals in the Southwest and worked at the Museum, 

 1871-72; 2 George Robert Crotch (1842-74), a British student of the 

 Coleoptera and author of a very useful list of North American species 

 of the order published in 1873; and Eugene Amandus Schwarz (1844 

 -1928), a German who devoted his long life to the study of the North 

 American Coleoptera. From 1878 to the time of his death, Dr. 

 Schwarz was one of the most competent and genial entomologists of 

 the United States Bureau of Entomology. In this connection, men- 

 tion should also be made of Baron Osten-Sacken, who, though an 

 independent diplomat and savant, spent two winters (1873-75) in- 

 corporating his own extensive collection of Diptera and that of Loew 

 with the previously existing collections of these insects in the Mu- 

 seum. 



1 Some of Hagen's wise counsel was rather humorous. Thus he advised Pro- 

 fessor E. L. Mark, who as a young instructor in 1877 was giving a course on in- 

 sects and mollusks: "When you finish your lecture, be sure you at once withdraw 

 and do not allow the students to question you ! " (E. L. Mark in S. E. Morison's 

 "The Development of Harvard University Since the Inauguration of President 

 EHot, 1 869-1 929," 1930, p. 385.) 



•' See S. W. Geiser, "Naturalists of the Frontier," Southwest Review, 1929, 

 pp. 184-198, and " Professor Jacob Boll and the Natural History of the South 

 West," American Midland Naturalist, 11, 1929, pp. 435-452. 



