ARAXEIDA. 



501 



appears to have ;t digestive function similar to that of the pancreatic 

 secretion, inasmuch as it dissolves albumens and transforms amyloid 

 substances into sugar. The short rectum receives two branched 

 urinary (Malpighian) canals, and dilates in front of the anal opening 

 to the form of a vesicle (fig. 400). 



St 



FIG. 401. Heart and vascular trunks of Lycona, iu 

 lateral and dorsal view (after Clapareds). P, 

 Lungs ; (\ heart ; Ao, aorta ; O, eyes. 



Fw. 402. Sexuiil organs of a 

 Tegenaria (Philoicn) aomestiea, 

 with the abdomen in outline 

 (after Bertkau). T, Testis ; I'd 

 vas deferens ; Sf. stigma. 



The vascular system is not less highly developed (fig. 401). The 

 blood flows from the pulsating dorsal vessel placed in the abdomen, 

 through an anterior aorta into the ce- 

 phalo-thorax, and thence into lateral arte- 

 ries, supplying the legs, jaws, brain, and 

 eyes. The blood returns from these 

 organs into the abdomen, bathes the so- 

 called lungs, which are composed of 

 numerous flattened tubes, and then re- 

 turns to the dorsal vessel through three 

 pairs of lateral slits. 



The ovaries (tig. 397) are two racemose 

 glands surrounded by the liver ; the short 

 oviducts unite to form a single vagina, 

 which is usually connected with two long 

 receptacula seminis and opens on the 



,. e ,, . , Fn.. JOS. Terminal part of the 



ventral surface of the anterior part of the pe(llll , lllius of SegesMa ( 6 } with 



abdomen between the anterior stigmata. tfa e receptacle of the spermato- 

 , . phores (after Bertkau). 



Hie testes consist ot two long coiled 



canals with a common terminal duct, which likewise opens at the 

 base of the abdomen (fig. 402). 



