,20 



LEPIDOPTERA 



slender oesophagus through the length of the thorax, dilating when 

 it reaches the abdomen to form a tul)ular stomach ; before this 

 it is somewhat enlarged to form an indistinct crop, and gives off 

 a large diverticulum usually called a sucking stomach. According 

 to Burgess, this structure does not possess the function ascribed 

 to it hj this name, and he terms it a food-reservoir. The Mal- 

 pighian tubes are six in number, three on each side, and each set 

 of three miite to form a conimun tube opening into the posterior 

 extremity of the stomach ; behind them the alimentary canal 

 continues in the form of a slender, tortuous intestine, expanding 





Fig. 163. — Internal anatomj' of Lepidoptera. Section of the body of a female butterfly, 

 Anosia plexipjms. (After Scudder.) The portion to the left of the vertical line 

 more magnified. I. II. III. thoracic segments ; 1-9, abdominal segments ; a, 

 antenna ; a, anus ; «c, aortal chamber ; ag^, etc., abdominal ganglia ; agl^, agl-, 

 accessory glands ; uo, aorta ; hr, brain ; c, colon ; cji, copulatory pouch ; cx^, ex-, 

 c:i?, coxae ; fr, food-reservoir ; (/, suboesophageal ganglion ; A, dorsal vessel ; i, 

 intestine ; //;;, area filled by wing muscles ; Lor, ovary, or egg-tubes of left side ; 

 riiv, Malpigliian tube (the two others of the right side cut away, except small por- 

 tions) ; iii.c, ma.xilla ; o, oviduct ; oo, its orifice ; ue, oesophagus ; ov.c, end of left 

 ovary ; p, labial palp ; ^^/t, pharynx ; r.ov, terminal parts of right ovarian tubes, 

 turned to one side, after the tubes have been cut away ; sd, salivary duct ; sgl, 

 salivary gland ; sp, spermatheca ; st, stomach ; tg, thoracic ganglia ; r, cojiulatory 

 orifice. 



at the extremity of the body to form a rectum. The dorsal or 

 circulatory vessel commences near the posterior extremity of the 

 body, but in the front part of the al}donien is deflexed to pass 

 under the great phragma into the thorax, where it rises abruptly 

 to the dorsal wall, but is again abruptly deflexed, forming a loop, 

 and is then prolonged above the oesophagus into the head : at 

 the summit of the thoracic loop there may be a dilatation called 

 the aortal chamber. The supra- and infra-oesophageal ganglia 

 are consolidated into a mass pierced l^y the oesophagus : there is 

 a minute frontal ganglion ; the ventral chain consists of three 

 much approximated thoracic ganglia and four abdominal ganglia 

 separated from the thoracic by a long interval. 



