544 
Flowers and Insects. 
[September, 
of the “ Jahrbuch des Botanischen Gartens, Berlin,” and of 
the “ Naturforscher.” , . , 
Prof. Low takes up in particular two questions : he 
examines the relation between the circle of visitants and 
the selection of flowers visited in a definite area of observa- 
tion, whose constituents are heterogeneous, being accident- 
ally made up of plants of very different origins. Second y, 
he examines what colours, under otherwise identical cir- 
cumstances, are preferred by the insert visitants. The field 
of observation was the Berlin Botanical Garden : 205 species 
of inserts were noticed as visiting flowers,— namely, 102 
Hymenoptera, 66 Diptera, 22 Coleoptera, 13 Lepidoptera, 
and 2 Hemiptera. This is about one-fourth of the species 
which Muller, in his work on the fecundation of floweis, 
mentions as flower-frequenters. We may here not a 
somewhat extraordinary the paucity of butteiflies and 
moths, especially as Germany is far richer in these inserts 
than Britain. It is very probable, Judging from 0111 own 
observations, that if a plot of ground had been selerte 
some 10 or 20 miles from any large town the proportion ot 
Lepidoptera would have been gieatei. _ . r 
Prof. Low observed 2000 insert visits to 578. species of 
plants cultivated in the open air. The plants in question 
belonged to three distinrt zones. The first zone comprised 
plants of the forest-territory of Europe and Asia. *n the 
second group were included all plants of the Mediterranean 
region, and of Western Asia, a region whose insert fauna 
differs from that of Central Europe and Asia more widely 
than do the various parts of the Central European and 
Asiatic region from each other. The third zone comprised 
plants indigenous in America or Eastern Asia, whose homes 
have an insert fauna still more widely differing from that of 
Central Europe. Plants of other origins were not taken 
into consideration. 
It is well known that Muller seeks to answer the question, 
what species of inserts are especially artive as pollen-dis- 
tributors in a given kind of plant. Low takes up the inverse 
question : what selertion does each insert species make 
among the flower-forms and colours presented to its view i 
Such an examination of the subjert from the entomologica 
side was necessary, as only thus can a clear insight into the 
abundance of the farts be obtained. 
In accordance with this principle Low has arranged his 
materials not according to plant-species, but to inserts. 
Hitherto only the first part of his researches has been made 
public, — that treating of the Apidae. Of these he has oh- 
