THE BroLocy oF THE CHRYSOPIDAE 1321 
Color changes and later development 
As the pupa develops, the body changes to a distinct bright green. 
The head, however, retains the yellowish color in most species. The 
eyes change from a gray to a deep reddish black. As the eyes develop, 
the retinulae are outlined by little circles of brown pigment forming 
regular geometrical figures. If these figures be examined under high 
power, they will be seen to consist of seven rhabdom cells outlined in 
pigment, with a small, clear, central area. This offers an excellent 
opportunity to study the gradual deposition of pigment in the develop- 
ing compound eye. 
In the early pupal stage, the head is unmarked, but gradually the 
head coloration of the adult appears. Chrysopa oculata shows very 
strikingly the dark bands and loops, but C. nigricornis does not show 
the two labral dots at first. These are developments in the early adult. 
The basal part of the legs becomes light green, while the tarsi remain 
grayish to translucent. The legs of the adult can be seen developing 
within the pupal legs, at first faintly but later very plainly. The 
developing antennae of the adult may also be thus seen. The wings, 
continuing their growth, soon fill the pupal pads. They then double 
up, forming regular loops back and forth. This explains how the large 
wings of the adult can develop in such small pads and be pulled from 
the pads so easily. As soon as this folding occurs, the tracheation and 
venation are obscured. The hairs on the wings show clearly and 
obscure most of the wing surface. 
These developmental changes can be followed by the external 
appearance of the cocoon. As the color of the larva fades to yellowish 
or gray, the cocoon takes on a tint of the same color. The cocoon, as a 
whole or in spots, at least after pupation of the larva, has a greenish 
tinge. In cocoons containing nearly mature pupae, the eyes can often 
be seen as two dark spots. When these eye spots are the darkest, the 
green color the most noticeable, and the black disk the most evident, 
the pupa may be expected to emerge. 
Cocoons that were wholly black were sometimes found. This gen- 
erally indicated that the prepupae within were dead, often parasitized. 
In cities, black or very dark cocoons were frequently found on trees, 
but some of these had been discolored by soot or smoke. Fungous 
growths on a cocoon have been observed to be positive evidence of the - 
death of the pupa or the prepupa. 
