liii 



flowers of the Upper Alps. One curious point I may refer to, 

 namely, that proterogynous flowers frequently — as, for instance, 

 among the Saxifrages — increase in size during their period of 

 bloom, so as to be larger in the male than in the earlier female 

 condition ; while proterandrous flowers never do so. The reason 

 of this obviously is the advantage in the male flowers being first 

 visited.* He observes that butterflies prefer red and blue flowers, 

 especially the latter, to those which are yellow or white. It 

 is interesting that the same love felt by butterflies for these 

 colours, which, by means of sexual selection, has probably tended 

 to their frequency and beauty on the insects themselves, should 

 in another manner have led to their frequent presence and 

 brilliant beauty on the flowers which they love. With reference 

 to this point he gives the following curious facts : — Out of every 

 hundred visits of insects observed in flowers which are white, 

 whitish yellow, or yellow, on the one hand, or, on the other, red, 

 violet, or blue, there were of — 



Diptera with a short proboscis 



Coleoptera 



Diptera with a long proboscis 

 Hymenoptera, excluding Bees 

 Bees with a short proboscis . 



Lepidoptera 



Hive Bees 



While, in the case of the parasitical Humble Bees, the numbers 

 are respectively 22*2 and 77'8, which he accounts for on the 

 hypothesis that these bees, having no need to work for their 

 young, are more free to follow their own tastes. 



We owe to M. de Saussure a short but important memoir on 

 the genus Hemimerus, an insect which has much the appearance 

 of a young cockroach, or mole-cricket, with which group it has 

 in fact hitherto been classed. M. de Saussure states, however, 

 that the mouth possesses an extra pair of a^Dpendages, con- 

 stituting a third pair of maxillae, and resembling a second lower 

 lip. This remarkable character would separate it, not only from 

 the Orthoptera, but from all other insects, and m M. de 

 Saussure's opinion necessitates the creation of a new section of 



- Kosmos, 1880, p. 280. 



