PAMMEL POLLINATION OF PHLOMIS TUBEROSA. 25 I 



but also occurring in Middle Europe ; the last is an inhabitant 

 of the southern and warmer regions of Europe. 



The examples of flowers perforated by Bombus terrestris show 

 that it mainly pierces those from which it cannot get nectar in a 

 normal way. Miiller (87 a) has found this interesting difference 

 between its visits to flowers on the plains and valleys and to those 

 of alpine and sub-alpine regions ; that while in the lower re- 

 gions it perforates many flowers where the nectar is in part acces- 

 sible to it, e.g. Vicia cracca and Salvia pratensis, on the other 

 hand Linaria alpina, Pedicularis asplenifolia, P. ttiberosa and 

 Trifolium ■pallescens are visited in a normal way in alpine regions. 

 Miiller also found a constant difference in the length of its 

 tongue. In the Alps its tongue was usually 8-1 1 mm. long, while 

 in the lowlands only 7-9 mm. long. Bombus terrestris is one of 

 the most abundant of European humble-bees, and this is perhaps 

 one reason why it uses these illegal means to get nectar. But B. 

 masirucaius, as Miiller's (87) investigation shows, is the worst 

 enemy to alpine flowers. Notwithstanding that its tongue is of 

 sufficient length to enable it to reach the nectar of such flowers 

 as Pedicularis iuberosa, Vicia cracca, and Linaria alpina, it perfo- 

 rates them, and only pollinates such flowers as Taraxacum, Leon- 

 todon, Carduus, Epilobium, and others of this class, which it could 

 not well perforate unless it were to go to more trouble than get- 

 ting the nectar in a normal way involves. 



Miiller has designated this as a case of dystelology,* as the 

 mutual relations which exist between flowers and insects are de- 

 stroyed and floral contrivances rendered inoperative by the actions 

 of this bee. Loew (63 a) would call it rather a case of dishar- 

 mony, since there is developed in Bombus mastrucatus a morpho- 

 logical character (the small teeth on the mandibles), useful in the 

 perforation of corollas. By disharmony he understands the non- 

 adaptation of certain insects to certain flowers ; for which rea- 

 son he thinks that some German species of Bombus perforate such 

 flowers as Lathyrus latifolius and Monarda didyma. This non- 



* For a discussion of the modern view of teleology see Haeckel's " Generale Morpholo- 

 gie der Organismen," "History of Creation," and "Evolution of Man"; also Dr. Asa 

 Gray's review of Darwin's •' Fert. of Orchids," Am. Jour, of Sci. & Arts, ser. ii. vol. xxxvi. 

 p. 3j. In Darwiniana, "Charles Darwin: A Sketch," p. 2S3; '"Evolutionary Teleology, "^ 

 p. 356; Delpino, and others. 



