Vol. XXVII. 



igto 



] H.\RDY, Mixed Pollen Collected by Bees. j\ 



MIXED POLLEN COLLECTED BY BEES. 

 By a. D. Hardy, F.L.S. 

 {Readheforntht Field Naturalists' Cluh of V^ictoria^ 13th Jiuie, 1910.) 



The November (1909) issue of the Journal oj the Department of 

 Agriculture, Victoria, contained a lecture by Mr. R. Beuhne, the 

 president and technical secretary of the Victorian Apiarists' 

 Association, entitled " Bees and Fruit Fertilization." Amongst 

 other matters of interest, one which particularly arrested my 

 attention was that to which the following quotation refers : — 

 " It is, however, a well-known fact that a bee during each 

 trip confines itself to one species of plant, whether in search 

 of nectar or pollen, and a mixture of pollen is never found in 

 any bee's load as it enters the hive ; plants of the same 

 species but of. different varieties are, however, worked on the 

 same trip." I take it that this remark was made after observation 

 on the field work of bees, but that the pollen was subjected to 

 macroscopic examination only, the colour of the collection being 

 the main guide. Mr. Beuhne presumably referred to the 

 domesticated bee {Ajns mellifica), in which case the statement 

 may hold good as a general rule. There are, however, excep- 

 tions, and with one or two such instances this paper is mainly 

 concerned. 



First allow me to quote a few authorities wholly or partly in sup- 

 port of Mr. Beuhne's remark. Professor A. J. Cook, of Pomona 

 College, Claremont, California (late Professor of Entomology, 

 Michigan State Agricultural College), says : — " It is a curious fact, 

 noted even by Aristotle, that the bees during any trip almost 

 always gather only from one species or bloom. From this fact we 

 see why bees cause no intercrossing of species of plants. They 

 only mix the pollen of different plants of the same species." The 

 constancy of the bee in its attention to the bloom of one species 

 during an outing from the hive has often been referred to, but 

 there are, I think, fewer, if any, references to the collection of pollen 

 by native bees. Having frequently observed imported bees visit- 

 ing unlike flowers in search of nectar or pollen (or at times both), 

 I caught some which had been visiting distinct species of plants 

 while gathering pollen exclusively. Most of these had homogen- 

 eous pollen in their baskets, and one which was taken in the act 

 of removing pollen from a yellow-centred white dahlia had 

 gathered from this form only, notwithstanding its having just 

 previously settled on such unlike flowers as purplish petunias, 

 red and white roses, &c. I am not dealing with pollen adhering 

 accidentally (as far as the bees' seeming intentions are concerned) 

 to haiis on various parts of the body, but to the deliberate 

 collection of grains by means of the baskets. In the pollen 

 masses of several I found that, while one form of pollen grain 

 predominated, grains of other species were to be found — e.g.^ 



