578 



Ueber Blumen und Insecten. 



In another Lantana the flowers have the colour of lilac, the entrance of the 

 tube is yellow surrounded by a white circle; these yellow and white markings 

 disappear on the second day. 



Mr. Leggett's statements about Pontederia cor data appear to me rather 

 strange, and I fear that there is some mistake. In all the five species of the 

 family which I know the flowers are so shortlived, lasting only one day, that a 

 change in the length of the style is not very probable. In the long-styled form 

 of our highland Pontederia the style has its full length long before the flowers 

 open. In my garden this Pontederia is visited by some species of Augochlora 

 collecting the pollen of the longest and mid-length stamens ; they are too large to 

 enter the tube of the corolla, and have too short a proboscis to reach the honey ; 

 they can only fertilise the long-styled and mid-styled forms, but not the short- 

 styled. 



Among the secondary sexual characters of insects the meaning of which is 

 not understood, you mention ("Descent of Man," vol. i., p. 345) the different neu- 

 ration in the wings of the two sexes of some butterflies. In all the cases which 

 I know this difference in neuration is connected with, and probably caused by, 

 the development in the males of spots of peculiarly-formed scales, pencils, or other 

 contrivances which exhale odours, agreeable no doupt to their females. This is 

 the case in the genera Mechanitis, Dircenna, in some species of Thecla, &c. 



Blumenau, St. Catharina, Brazil, October 19 1876. (?) 



