atures distinguished by the curious conformation
of the mouth and by a lateral row of dots that may represent the
metameric spiracles or, as commonly, a demarcation between dorsal and
ventral surfaces. That these are maggots of a blow-fly (_Sarcophaga_)
there can be little doubt, not only on account of their mouth parts
which are similar to those of the agave maggot (see later) but also
because of their relation to God F whom they are devouring. The latter
in fig. 1 is doubtless dead as shown by the closed eye and it is the
habit of the blow-fly to deposit its eggs in the nasal cavity of dead
animals as well as elsewhere on the body. The fact that in each case a
maggot is attacking the god's nose may indicate that this habit was
known to the artist who, consequently, shows the larvae in this
position. In Pl. 3, fig. 2, the god's eye is not closed but his passive
attitude while the maggot devours his hand and nose does not indicate
that he is in full possession of his strength. In addition to the
blow-fly, a screw-fly (_Chrysomyia_) lays its eggs on the bodies of
animals, often on persons sleeping, and these may hatch almost at once
into small maggots that penetrate the skin. It may be, therefore, that
the larvae here considered belong to this genus.

In addition to god F, in Tro-Cortesianus 24d, there is another
representation of the same god being attacked by a vulture. This bird is
evidently eating his nose. In this case the god is shown with the closed
eye as in 27d. In Tro-Cortesianus 25d the fly seems to be attacking the
mouth of god F. From the fact that no other god is ever found in this
connection it may be suggested that there may be some relation between
god F as a god of human sacrifice and the fact that his dead body is
being eaten by blow-flies and vultures. A portion of the body of the
person sacrificed was usually eaten by those taking part in the
ceremony.

LEPIDOPTEROUS INSECTS. In Tro-Cortesianus 28c (Pl. 3, fig. 3) is shown a
second insect larva with curiously formed mouth parts. It is represented
as attacking agave which is springing from the ground as shown by the
_Caban_ signs in the codex. Hough (1908, p. 591) has shown this to be
the larva of _Acentrocneme kollari_ Felder, "called by the Mexicans
_guson_, and in Nahuatl _mescuillin_." This grub, he says, is white,
about an inch long, and tunnels the fleshy leaves of the agave. It is
greatly prized as an article of food for "_gusones_ to this day