322 DAVENPORT ACADEMY OF NATURAL SCIENCES. 



conceal the form of the insect, as is the case in many Coccidae. This 

 wax is more or less soluble in alcohol, chloroform, ether, turpentine and 

 almost any oily substance, but appears to remain unaffected by water, 

 glycerine, nitric and acetic acids, etc., and renders the insect quite water 

 proof. 



It is by no means improbable that a more careful study would reveal 

 a greater variety in the forms of these wax-secreting glands. The form 

 described and figured (fig. 44) appertains to the ventral tubercular pores, 

 and I think those of the spines and dorsal pores can not be very differ- 

 ent,— but still they may be. 



The nervous systevi (fig. 48) consists of numerous nerves centering in 

 two large ganglia. The anterior, cephalic, or suptra-cesophagal gan- 

 glion, (a) is triangular in form with the sides convex, and, so far as I 

 have been able so detect, without any indication of a bilateral division. 

 It lies immediately in front of the mouth parts with the smaller end di- 

 rected backward and dividing into two commissures, allowing the oeso- 

 phagus to pass upward between them, while they continue on, passing 

 between the arcus superior and arcus inferior and thence through an 

 opening in the area superior and over the posterior parts of the costce su- 

 periores. During this passage they become again united and gradually 

 enlarged into the infra- ce.sophagal or thoracic ganglion (b). This is a large 

 somewhat pointed oval body, whiUi shows obscure indications of a bi- 

 lateral division and also of four or more transverse divisions. It is con- 

 tinued backward in a rather large ventral cord (e) which I have traced 

 a distance equal to about the length of the thoracic ganglion without 

 finding any branches or abdominal ganglia. It .probably supplies the 

 large nerves about the vagina, etc. From the posterior half of the tho- 

 racic ganglion two nerves (k and c) are seen to start out on each side, 

 and the most posterior (c) of these almost immediately sends off a branch 

 {d) thus making three nerves on each side. I have not traced the 

 ultimate destination of these, they may very probably supply the nerves 

 of the legs, or they may in addition send branches to other organs. 

 From the anterior angles of the cephalic ganglion proceed the large optic 

 nerves (m) to the eyes. As they approach the eyes they become enlarged 

 and filled with dark reddish granular matter. From the under side of 

 the cephalic ganglion extend two smaller nerves [l) to the antennae, and 

 in all probability there are others to the mouth parts and other organs 

 which I have not seen. Numerous small nerves are found in various 

 parts of the body, but I have not traced their connections. Both nerves 

 and ganglia appear to consist of a grayish granular substance inclosed 

 by a thin transparent membrane. 



There are nunyerous muscles, but I have made no attempt to study 

 them. In structure the muscles are composed of fibres transversely 

 striated. There are very numerous muscles in the vicinity of the anus 

 and of the vulva. There are also some indications of muscles attached 

 {;0 the conical bases of the buccal setae, and in Cicada I have actually 

 observed this to be the case. 



