JOURNAL OF ENTOMOLOGY AND ZOOLOGY 199 
Haller 712, homologizes areas in the spider and scorpion brain 
to the mushroom bodies of other arthropods. These areas are 
located in the dorso-lateral portions of the nervous system in 
cephalic and caudal regions. These areas are marked by clusters 
of small nerve cells and small clear areas in this region. In 
Chelifer all the cells are about the same size; there are, however, 
little clear areas in the same general regions of pseudoscorpions, 
There are two areas on each side of the brain dorsally just in 
front of the great caudal dorsal mass of cells and just back of 
the cephalic dorsal mass. These little areas are almost free 
from cells and they seem to be the only indications of anything 
like mushroom bodies. 
In some specimens the fibers are intensely stained and at 
certain areas such as the region just under the large cephalic 
mass of cells on either side of the brain, fibers extend down from 
the cell areas of the brain. It is possible that some of these fibers 
represent connections which correspond to the mushroom fibers. 
IMPORTANT CONCLUSIONS 
1. There are no important abdominal ganglia beyond the 
fused mass of the central nervous system. 
2. The pedipalpal nerves are the largest. 
3. A small number of simple more or less straight tracheoles 
penetrate the nervous system. 
4. There are few deep-staining masses of fibers. 
5. The cells have very little cytoplasm. The nuclei are 
usually provided with six or more chromatin granules. 
6. The sense organs so far as determined are: a pair of 
simple eyes and hollow sete provided with nerves from bipolar 
nerve cells. 
7. The cells of the brain are largely unipolar, but other 
forms are found. 
8. The neuroglia cells form a network of their fibers and 
this network between nerve cells serves as a sort of sheath for 
them. The fibrous part of the nervous system also has strands 
from neuroglia cells and this forms a support for the nerve fibers 
which run in various parts of the ganglia. 
