LITERATURE CITED. 



(1) Armstrong, J. B. 



1883. The fertilization of the red clover. In Gard. Chron., n. s., v. 20, no. 516, 

 p. 623-624. 



(2) Beal, W. J. 



1887. Grasses of North America, v. 1. New York. 



(3) 



1907. Planning an experiment to show to what extent bumblebees aid in pollin- 

 izing red clover. In Proc. 28th Ann. Meeting Soc. Prom. Agr. Sci., 

 1907, p. 136-138. 



(4) Bolley, H. L. 



1907. Fertilization of clover and alfalfa. In N. Dak. Agr. Exp. Sta. 17th Ann. 

 Rpt. [19061/07, p. 34-35. 



(5) Cook, A. J. 



1892. Report of apicultnral experiments in 1891. In U. S. Dept. Agr. Div. Bui. 

 26, p. 83-92. 



(6) Darwin, C. R. 



1885. The Effects of Cross and Self Fertilization in the Vegetable Kingdom. 



New York, 482 p. 



(7) 



1898. The Origin of Species ... . v. 1. New York. 



(8) Dunning, J. W. 



1886. [Report on importation of humblebees into New Zealand.] In Proc. Ent, 



Soc. London, 1886, p. xxxii-xxxiv. 



(9) Fertilizing clover and cow-grass. 



1891. In Agr. Gaz. N. S. Wales, v. 2, pt. 10, p. 636. 



(10) Folsom, J. W. 



1909. The insect pests of clover and alfalfa. 111. Agr. Exp. Sta. Bui. 134, p. 

 113-197, 35 figs., 2 pi. (1 col.). 



(11) Fruwirth, Karl. 



1906. Enclosing single plants and its effect on a large number of important agri- 

 cultural species. In Amer. Breeders' Assoc. Proc, v. 2, p. 197-198. 



(12) 



1906. Die Ziichtung der landwirtschaftlichen Kulturpflanzen. Bd. 3. Berlin. 



(13) Genevier, Gaston. 



1876. Inflorescence et fecondation dans le genre trifolium. In Assoc. Franc. 

 Avan. Sci. Compt. rend., 4th sess., 1875, p. 726-730. 



(14) Hopkins, A. D. 



1896. On the flowering habits of timothy and red clover and the pollenization of 

 the flowers by insects. In Proc. 17th Ann. Meeting Soc. Prom. Agr. 

 Sci., 1896, p. 35-40. 



(15) — - 



1896, Some notes on observations in West Virginia on farm, garden, and fruit 

 insects. In U. S. Dept. Agr. Div. Ent. Bui. 6, n. s., p. 71-73. Also in 

 West Va. Agr. Exp. Sta., 9th Ann. Rpt. [18951/96, p. 152-155. 



29 



