The Grasshopper 



341 



crystalline product while those, which live in damp places, excrete the 

 soluble form. 1 



The excretory products leave the body through the urinary or 

 Malpighian tubules which empty into the intestine just posterior to the 

 stomach, thus causing both the excreted and egested material to leave 

 the body in the same way. These tubules ramify throughout the body 

 in the animal and are very conspicuous when the body is opened. 



THE NERVOUS SYSTEM 



The nervous system resembles that studied in the crayfish. A 

 series of ganglia lie along the ventral nerve cord which splits at the 



Fig. 222. 



Reproductive system of the Queen honey 

 bee. a, accessory sac of vagina; b, bulb of 

 stinging apparatus ; c, _ colleterial, or cement 

 gland ; o, ovary; od, oviduct; p, poison glands; 

 pr, poison reservoir; r, receptaculum seminis; 

 re, rectum; v, vagina. (After Leuckart.) 



Fig. 221. 



A, diagram to illustrate the action of 

 wing-muscles of an insect. 



B, diagram of wing-muscles. a, alimen- 

 tary canal; en, muscle for contracting thorax, 

 to depress wings; d, depressor of wing; e, 

 elevator of wing; ex., expandor of thorax to 

 elevate wing; id, indirect depressor; ie, in- 

 direct elevator; /, leg muscle; p, pivot or ful- 

 crum; s, sternum; t, tergum; wg, wing. 

 (After Grabers.) 



oesophagus, one half passing dorsad on each side of that organ to 

 unite again on the dorsal surface to form the supraoesophageal ganglion 

 or brain. The ganglion below the oesophagus which branches to permit 

 the passing around to form the brain is called the suboesophageal 

 ganglion. It is from the brain that nerves go forward to supply the 

 special sense organs, such as the eyes, antennae, and labrum, while the 

 mandibles and maxillae are supplied from the suboesophageal ganglion. 

 Nerves are given off from the thoracic and abdominal ganglia to all 

 parts of the respective segments. The interesting thing about insects 

 is that these nerve centers seem to be as independent as are the separate 



x Doubt has been thrown on former investigations by recent work, so it is well not to assume 

 that our opinions in regard to the work of the Malpighian tubules or of the formation of urea 

 are final. 



