106 
BETTISH APHIDES, 
The Male. 
There appears to be some discrepancy amongst 
authors as to the form of this rare insect. De Geer, 
who seems first to have met with it, does not even tell 
us whether it is apterous or not. Amongst the 
companies of Aphides he kept in his chamber, he says 
that probably he possessed as many as 200 oviparous 
females. He observed amongst these only three or 
four males,” which he often saw in union with these 
females. He remarks that the coitus is long, just as 
he noticed was the fact in respect of the milfoil Aphis. 
Kyber at the beginning of winter introduced a 
number of males and females into an artificially 
warmed chamber, and found that the females still 
continued to oviposit, and never once produced their 
young alive. He thus showed that if a low tempera- 
ture could cause, as he thought it could, the appear- 
ance of the digenetic forms of Aphides, a warm climate 
was incapable of producing the converse phenomenon, 
viz. that of causing the parthenogenetic form, in 
other words, of converting the oviparous into the non- 
sexual viviparous character. 
Newport performed a somewhat similar experiment, 
but for a different purpose. He placed four apterous 
individuals of S. rosce in confinement, two of which he 
considered to be males. The result of his experiment 
shows, however, the extreme probability that the latter 
were only varieties of the viviparous female, which 
alone will account for the unexpected simultaneous 
appearance of both eggs and living young. 
Mr. F. Walker says that the male of S. rosce is 
winged, with a black head, dark thorax, and green 
abdomen. 
In this description also Dr. Eichar^dson agrees, and 
he further implies that the male is always winged.^ 
Koch observed early in July some small winged 
/ Aphides mixed with numerous apterous and larger 
^ ‘ Phil Trans./ Ixi, 121. 
