104 
HALF HOURS WITH INSECTS. 
[Packard. 
project out from near the end of the body. From these two 
tubes issues the so-called honey dew, the delight of the sweet 
toothed ant. When a brood of aphides are busily engaged 
in tapping the stems of some plant, and the honey dew is 
dropping upon the ground or leaves below, a procession of 
sable ants enliven the scene. 
This sweet fluid is also designed to afford nourishment for 
the young as soon as hatched. Both Bonnet and the Belgian 
naturalist Morren observed that the young Aphides as soon as 
born sucked up the fluid with their beaks, and thrived upon 
that for a while, before attacking the juices of the plant itself. 
It has been a matter of curiosity to us how this thin fluid 
is secreted. Morren* has demonstrated that these tubes are 
in reality modified respiratory organs, as Bonnet had sup¬ 
posed. They are simply tubular elongations of the skin 
with a hole at the end, into which the air enters, while the 
sweet fluid escapes from the same hole. On dissecting the 
little creature, a task requiring much time and patience, 
Morren found a net-work of air tubes (tracheae) near the base 
of each tube. This tube, he says, is “only a prolonged 
stigma, and it becomes evident that it is the air of these tra¬ 
cheae which forces out the fluid with which this appendage 
is often filled.” At the base of the tube he also found a 
gland which secretes the sweet liquid. The latter passes 
into the tube or excretory canal at the same time as the air 
within presses out. The viscous liquid is thus thrown out 
during expiration. Morren tells us that he has “several 
times seen the young Aphides suck the end of these tubes 
while holding their beaks near it. This always happened 
whenever I was able to have the females bring forth their 
young in vials without any leaves to serve as food for either 
the young or its mother. Now a gland situated on the sur¬ 
face of the body, provided with an excretory canal, and se¬ 
creting a sweet fluid intended to nourish the young is in fact 
♦Annales des Sciences Naturelles. Tome 6. Second series, 183G. Paris. 
8 
