1923] 
Flower Visits of Insects 
159 
Percentages of visits to red flowers are given for the Berlin 
Garden and Low Germany (Loew 2 , 3 ) and the Alps (Muller 
5,512-23). The percentages of red flowers observed are for the 
Alps 41.6 and Berlin Garden 48.2. In 31 cases, all except Sphingidse, 
the percentage of local visits to red ranges from 5.4 to 51.3 less, 
or an average of 24. The term preference, as used here, means 
only that the percentage of visits is greater than the percentage 
of flowers observed. For each group the percentages of flowers 
visited as well as the visits were distributed under each flower 
class. Usually these are much alike, so that the percentages of 
flowers visited are not mentioned except when they are quite 
different from the visits. 
The flowers were also divided into an early group containing 
235 plants, 142 blooming, and 33 observed, before July, and a 
late group containing 262 plants, 144 blooming, and 58 observed, 
after June. In the case of 60 plants the visits observed before 
July and after June were referred to each group. Of these 60 
plants 13 are not native. Visits to these groups were first dis- 
tributed under Muller’s classes. Before July there are maxima 
under B, AB, including Po, and A. After June there is a slight 
increase inHb, including 0 and F, and a marked increase in B'. 
The visits to these groups were also distributed under the 
new classes. The early group shows maxima of the simplest 
flowers, non-social Mi, and white colors. These along with Mis 
decrease in the late group, which shows maxima of Ma and red, 
and a great increase in Mas. The specialization of the late 
group is marked by the increase of the social flowers from 38.7 
to 54.1 per cent. 
When B' as an element of the flora changes from 8.0 to 28.2 
per cent, the maxima of the insect groups change from the four 
other dominant classes to B'. The only exceptions are the 
ruby-throated and the Non-aculeata. The maxima of the same 
insects, when distributed into early and late sets of the new 
categories, in 62.8 per cent of the cases, fall under the same 
flower groups. 
The Bombidse, Euceridse, Anthophoroidea, Dasygastrse and 
long-tongued bees in general change from Ma to Mas, due to 
the fact that Mas is not well represented in the early flora. 
