765 
No. 145.] 
rine matters are kept, and it is for the purpose of feeding upon 
the honey-dew that the aphides secrete so copiously that they are 
such constant attendants upon these insects. The mode in which 
they obtain this from the plant lice is quite interesting; with 
their long flail-shaped antennae they gently touch the backs of the 
plant-lice, whereupon these eject this sweet fluid, which stands in 
the form of a small clear drop at the tip of one or both of the 
nectaries or little horns towards the end of their bodies. This 
the ant immediately sips, and by passing from one aphis to an¬ 
other he obtains his fill of this delicious sweet. A family of ants 
is thus supplied with an important part of its nourishment by dis¬ 
covering a tree on which the aphides have located themselves, 
and thereafter one after another of the ants may always be seen 
passing up and down the trunk of the tree. Plant-lice have hence 
been styled the kine or cattle of the ants, as they come to them 
regularly to milk them as it were, and in return for this savory 
food which they furnish the ants, some of the latter remain con¬ 
stantly by them night and day to protect these small weak crea¬ 
tures from being molested by their insect or other enemies. Thus 
before we are able to inspect a colony of plant-lice we are first 
obliged to brush off or destroy the ants which are guarding them, 
and I have frequently noticed that when a colony of aphides 
is newly established, and before it has been found by these in¬ 
sects, it remains small and does not thrive and increase so rapidly 
as when nursed and guarded by these industrious heroic creatures. 
Thus a colony of the Cone-flower plant-louse (Aphis Rudbeckia) 
a species which I described in the Fourth Report of the State 
Cabinet, page 66, which has been established more than a fort¬ 
night upon a stalk of golden rod ( Solidago) near my door, al¬ 
though it has not been molested by any destroyer, numbers only 
twenty-five individuals, and these are scattered about upon the 
stalk and leaves, seemingly pining in want of their accustomed 
attendants to herd and nurse them. 
The species of ant which I have most frequently met with, asso¬ 
ciated with plant-lice upon the apple treb, is a large black ant, 
with a dark red thorax, and is very similar in its size and colors 
to the wood-eating ant, (Formica herculeana , Linn. F. lignivora , 
