1918-19.] Life-History and Bionomics of Myzus ribis , Linn. 85 
Flogel (10, 11), who described the structure of the species minutely, 
asserted positively that “ on the fifth joint are about eight sensoria.” 
(For the views of later observers see section Myzus whitei and 
Myzus dispar.) 
Fig. 2. — Range of variation in Joint V of the antennae, in 
respect of the sensoria, of seventeen sister females of 
the green -leaf type. 
Between June 8th and June 23rd I made a collection of winged forms 
from my garden ; the results are set out in the table below. 
Table D. 
Collections of winged females from red blister and green leaf to show the 
type of antenna. 
1 
Total 
Red Blister 
Type. 
Green 
T yi 
Leaf 
ie. 
Undetermined. 
Number 
collected. 
Number. 
Per 
cent, of 
Total. 
Number. 
Per 
cent, of 
Total. 
Number. 
Per 
cent, of 
Total. 
Red blister collection . 
174 
173 
99-4 
i 
•05 
Green leaf collection . 
73 
6 
7*19 
65 
78-2 
12 
143 
The occurrence of the red blister type in the collection from green 
leaves may possibly be explained by the fact that the winged females are 
