372 Mr. F. Walker on the Migrations 0 / Aphides. 
Fig. G. Brachiolites racemosns : the right-hand portion shows the form of the 
arms as seen on outside of flint; the left-hand portion shows the 
root and longitudinal sections of several arms, p. 364. 
— 7. Brachiolites tubulatus^ p. 366. 
PI. XVI. (all in chalk). 
Fig. 1. Brachiolites foliaceus : the lower part showing the outside, the upper 
part a vertical section, p. 364. 
— 2. Brachiolites digitalus, p. 365. 
— 3. Brachiolites fenestratus, p. 367. 
— 4. Brachiolites labrosvs, p. 368. 
— 5. Brachiolites protensus, p. 369, 
XLL — Remarks on the Migrations 0 / Aphides. 
By Francis Walker, F.L.S. 
f’rom the great Author all that lives 
its stated boon of life receives. 
Ere long again restored to thee ; 
Each insect too minute to name 
Yet owns a portion of thy flame, 
Part of tliy numerous family. 
Resplendent cars of fiery glow 
From realms of light to earth below 
'J'hy animated offspring bear ; 
And when this mortal trial ends, 
Again the glorious car attends 
To wing them to their native sphere. 
Lorenzo de Medici. 
In the following notice I have enumerated some of the species 
of Aphis that migrate at regular periods from one kind of plant 
to another, or whose food has been partly altered by the cultiva- 
tion of plants. Aphis Rosa migrates from the rose to the teazel ; - 
A. dirhoda from the rose to grasses and dags, and the introduc- 
tion and growth of corn have afforded it a new nourishment, and 
have consequently modified its habits ; and the cultivation of va- 
rious species of rose brought into this country has also increased 
its food, and that of A. Rosa and of the three following species : 
A. trirhoda migrates from the rose to the columbine, and this 
change of food is probably not aboriginal, but consequent on the 
cultivation of the latter plant. A. tetrarhoda and A. Rosarum 
appear to live only on the rose genus. A. Avena has its first 
habitation on grasses, and the cultivation of corn has furnished 
it with a new and abundant source of food. A. Caprea migrates 
from the willow to umbelliferous plants, and in this case both 
the winter residence and the summer pasture of the species are 
aboriginal. The food of A. Urticaria is divided between the 
nettle and the bramble, and both these plants are also original 
sources. A. Humuli lives permanently and aboriginally on the 
