648 The American Naturalist. [August, 
contact with fibers from the ventral cord, which exists, although 
Binet was unable to discover any “ growth of fibers connecting 
the cord with the brain.” 
The fibers entering the cups from the antennal lobe, the 
optic ganglia, and the ventral region, spread out and branch 
among the arborescent endings of the mushroom body cells. 
Fig. .—A. An “intellective” cell from the mushroom body. n, neurite; 
d. dendrite ; a.r., anterior branch of the neurite ; i.r., inner branch of the neurite. 
B. Mushroom body of right side from above. The outer one, m.b , viewed in 
section ; the inner one is cut off, leaving the stump of the stalk st. a.r., anterior 
root; i.r., inner root; m.b., cup. 
The fibers branching among the parallel fibers of the roots and 
the stalk lead off to lower parts of the brain, connecting with 
efferent or motor ‘fibers, or with secondary association fibers, 
that in their turn make such connections. This portion of the 
circuit has not been perfectly made out, though there seems to 
be sufficient data to warrant the assumption just made. 
Such fibers existing as described there is then a complete 
circuit for sensory stimuli from the various parts of the body to 
the cells of the mushroom bodies. The dendritic or arborescent - 
branches of these cells take them up and pass them on out 
along the parallel fibers or neurites in the roots of the mush- 
room bodies as motor or other efferent impulses. 
This, however, is not all. For there are numerous fibers © 
evident in my preparations, the full courses óf which I 
have not been thus far able to determine, but which are so 
