98 
Psyche 
[June-August 
filling much of the body-cavity from the sixth to the fourteenth 
segments. The two ovaries occur in the region of the tenth 
segments, and are closely connected anteriorly with fat-bodies. 
There are small chitinous points, arranged in four or more 
rows, extending around the larva between each segment from 
2 to 14. Six chitinous hooks terminate the larva in the last seg- 
ment. 
There are two tracheal trunks on each side of the body, one 
laterally ventral, one dorsal. These have numerous cross branches, 
viz., one large branch connecting the two dorsal trunks in each 
segment from 6 to 13. From each of these branches two other 
minute branches extend posteriorly in each segment. Numerous 
branches and sub branches proceed from the ventral trunks. 
The dorsal and ventral trunks are connected in each segment 
from 6 to 13, another branch opening to the exterior on each 
side thus forming eight pairs of stigmata. There being no pro- 
truding spiracles it would seem difficult for the larvae to remain 
long submerged. However, larvae remain alive for long periods 
of time, a fortnight or more, when completely submerged in 
water under a cover-glass. 
A series of large ganglia occur ventral to the digestive tube- 
Locomotion results from stretching each segment and then 
contracting it, the process extending anteriorly. The rows of 
chitinous points prevent the larvae from slipping. 
The size of larvae varies with species, individuals, cultures 
and age. New born paedogenetic larvae of Miastor metraloas, 
average 1.35 x 0.16 mm, while paedogenetic mother-larvae at- 
tain a length of from 3 to 4 mm. 
2) Yellow pcedogenetic larvce. 
Yellow forms (wanderers) are similar in general structure to 
white paedogenetic forms. They are extremely active. The 
body is usually slimmer, and the fat bodies less heavily developed 
than in white paedogenetic larvae. The yellow pigment seems 
to occur for the most part in the fat-bodies. The eyes are notice- 
ably larger than in other Miastor larval forms, and approach 
closely along their surfaces. 
