STEUCTUEE AND BIOLOGY OP SCHIZONEUEA LANIGEEA. 691 
the posterior face of the second pair of coxse. Two similar 
flexor muscles extend from the post-dorsal margin of the 
metathorax to the third pair of coxse. 
A stout flexor and extensor muscle extend from the walls 
of each coxa to become inserted on the base of the trochanter. 
A large extensor and a smaller flexor muscle extend 
throughout the femur. Inserted at the base of the tibia are 
a small flexor and extensor muscle^, which continue throughout 
the article to the base of the tarsus. 
(4) The Dorso-ventral Muscles of the Body. — 
Several bands of dorso-ventral body muscles extend from the 
floor of the thorax and abdomen to the dorsal and lateral 
walls of the body. 
The dorso-ventral muscles of the abdomen (m. v.) arise from 
the ventral surface, close to, or a little external, to the outer 
longitudinal muscle bands, and pass upwards to become 
inserted on the dorso-lateralpvalls of the segments. It is these 
dorso-ventral muscles which bring abont the I’espiratory 
movements of the body. 
From the ventral surface of the seventh and eighth 
abdominal segments a band of mnscles passes to each of the 
coniicles (m. corn.), and control the movements of the opening 
of those structures. 
The Pse udo-vitellus. 
Situated in the posterior half of the abdomen, lying by the 
side of, or between the ovarian caeca, are a few roundish 
conspicuous cells, which ai-e usually joined together ingroups 
of two or three cells, or in young females may form two larger 
masses (fig. 45, pv.). 
When stained in sections with haematoxylin and eosin, the 
cytoplastn of these cells readily takes the eosin stain and 
appears to be quite granular. In the centre of the cell is a 
deeply staining nucleus with a nucleolus, but in some cells the 
nucleus is not seen. 
These cells form the so-called pseudovitellus of Huxley and 
