152 Trails. Acad. Sci. of St. Louis. 



Jahren veroffentlichten Beobachtungsmaterials. Besides a 

 slight German bias it must be used with caution on account of 

 its time limit. I have had trouble with it because it mentions 

 an author's name without citing the paper in which the ob- 

 servations are recorded. 



For access to much of the literature I am indebted to the 

 authorities of the Missouri Botanical Garden. Owing to the 

 interest Professor Trelease has taken in the subject, the 

 library probably contains the best collection of the literature 

 of pollination in this country, and that, too, in the most con- 

 venient form for consultation. It is highly desirable to make 

 this collection as complete as possible. 



In the determination of Hymenoptera I have been aided by 

 Mr. E. T. Cresson, W. H. Ashmead, L. O. Howard and W. 

 J. Fox; in Diptera by Dr. S. W. Williston, C. H. T. Town- 

 send and D. W. Coquillett; in Lepidoptera by Prof . G. H. 

 French and C. A. Hart ; in Coleoptera by Mr. Hart, Chas. 

 Liebeck, through Entomological News, and S. Henshaw; in 

 Hemiptera by Mr. P. R. Uhler and Mr. Hart. 



Hepatica Dill. — Sprengel (1) regarded H. triloba as a 

 pollen-flower adapted to bees, and his view that the flower 

 contained no nectar is confirmed by Axell (3) Miiller (4) and 

 Loew (8). ]\Iiiller saw Erislalis tenax frequently feeding upon 

 the pollen and hive-bees collecting it. He also notes that the 

 male of Osniia rufa vainly sought for nectar, and that a but- 

 terfly, Oolias rhamni, rested upon the flowers and probed for 

 nectar upon different parts of the receptacle. Loew accounts 

 for the visits of Osmia rufa as a result of a scarcity of food 

 or as beino; in the search of the female. I have observed that 

 when male bees fly about flowers looking for the female, they 

 only do so about flowers upon which the female occurs, and 

 they seldom alight. I makie it a rule to capture these male 

 bees and to watch the flowers for the visits of the females to 

 which they belong. 



Miiller (6 ) goes to an extreme in mentioning Hepatica as an 

 example of the blue flowers specially attractive to the highest 

 specialized bees. The color is commonly quite pale, and the 

 indications seem to point to an adaptation to the least special- 



