178 ARTHROPODA 



(a) Female Reproductive Organs. 1 — Each ovary passes 

 inward and backward, anastomoses with the one of the other 

 side behind the stomach, and extends back to the abdomen. 

 On a level with the posterior part of the stomach a branch 

 passes downward and outward and is continuous with a 

 dense, white organ, the seminal receptacle. Leave this re- 

 ceptacle in place, but remove the entire ovary. 



(£>) Male Reproductive Organs. — The usually slender tes- 

 tis which is large during the season of activity passes inward 

 and backward, anastomoses with its fellow of the other side 

 behind the stomach, and is continued as a thick, much-coiled 

 tube, the vas deferens, to the median side of the flank. It 

 then runs forward nearly to the stomach, turns back again, 

 and enters the substance of the flank. By removing the top 

 of the flank and the upper side of the coxopod of the swim- 

 ming leg, it can be followed to its external opening. 



Digestive System. — 1. The liver is large and fills a large 

 part of the body cavity. Remove the portion of it that is in 

 the region of, and anterior to, the stomach, noting its con- 

 nection with the alimentary tract. 



2. The stomach is a chitinous box divided into a larger 

 cardiac and a smaller pyloric portion. On each side find the 

 duct from the liver, and a slender, white, coiled tube, the 

 pyloric caecum. 



3. Follow the delicate intestine back beneath the heart. 

 Between the posterior edges of the flank is a white mass com- 

 posed of a coiled tube, the intestinal caecum. Remove the 

 terga of the abdominal segments, follow this caecum to its 

 connection with the intestine, and follow the latter to the 

 anus, noting its chitinous lining. 



4. Cut out the alimentary tract, open the stomach, and 

 examine the grinding and straining apparatus. 



Make a drawing of the alimentary canal. 

 Excretory Organs. — Examine the antennary gland (green 

 gland) on the inside of the carapace opposite the base of the 

 1 The specimen must be large and mature. 



