266 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



under side of the infra-oesophageal ganglion arise three pairs of nerves, 

 which are distributed to the mandibles, maxillse, and labium. The man- 

 dibular nerves project forward and arise from the anterior part of the 

 ganglion, near the origin of the supra-cesophageal commissures, while 

 the maxillary and labial nerves are directed downward into those organs. 



The first thoracic ganglion is considerably larger than the infra-oesoph- 

 ageal, and lies on the floor of the body opposite the insertion of the fore 

 legs, and under the center of the protergum. The second thoracic gang- 

 lion is larger than the first, and lies a little behind the insertion of the 

 middle pair of legs, in the mesothoracic segment. It sends off a pair of 

 large nerves to the hind legs, the nerves arising a little in advance of 

 the middle of the ganglion. Five pairs of small nerves are distributed 

 (two to the organs of hearing) to parts, &c. lying in the base of the ab- 

 domen. Other nerves are distributed from the two thoracic ganglia to 

 the muscles of flight and walking. Of the five abdominal ganglia the 

 first is small and white, while those anterior to it are red j it is situated 

 in the third abdominal segment. The second abdominal ganglion lies 

 in the fifth abdominal segment. The third abdominal ganglion lies in 

 the seventh segment, the fourtji in the eighth segment, and the fifth in 

 the ninth segment. The fourth and fifth are near together, and 

 the fifth is considerably larger than the fourth, while the commissures 

 connecting them are much thicker than in the rest of the abdomen, 

 those between the second thoracic and first abdominal ganglia being 

 very small. (The remaining description is drawn up from dissections of 

 C. femur-rubrum. ) 



The last or fifth abdominal ganglion sends off a lateral nerve (Fig. 14, 

 thrown off just above the letters sh)^ which is distributed to the sebific 

 gland and bursa copulatrix. From the posterior edge of the ganglion 

 four nerves are distributed to the muscles Of each spine of the ovi- 

 positor in the female, and small nerves are distributed to the large air- 

 sacs. There is considerable variation in the distribution and number of 

 these nerves. The ganglion lies directly over the point of junction of 

 the two ovarian ducts which unite to form the common oviduct, and it 

 partly covers the sebific (or sebaceous) gland. 



The sympathetic ganglia are three in number; one situated just behind 

 the supra-cesophageal ganglion (Fig. 15, as), resting on the oesophagus, 

 and two others situated each side of the crop, low down. Each of the 

 two posterior ganglia is supplied by a nerve from the anterior ganglion. 

 Two nerves pass under the crop connecting the posterior ganglia, and 

 from each posterior ganglion a nerve is sent backward to the end of the 

 proveutriculus. A pair of nerves pass under the oesophagus from each 

 side of the anterior sympathetic ganglion, and another pair pass down- 

 W-ard to a round white body, whose nature is unknown (Fig. 15, u). 



The heart. — This organ (Fig. 14) is imperfectly understood in the locust, 

 and, indeed, in the Orthoptera generally. So far as we could discover, 

 the heart is a long tube, lying in the abdomen, dilating at six places 

 along its course, and ending in a conical point near the end of the ab- 



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