193 



between the two arise the pair of ducts which afterwards bifurcate 

 and become the four lobnlated uriuary tubes (u). Froni about tbe 

 point where tbe four urinary tubes combine into two single duels, 

 thèse ducts, togellier witb the ascending ventricle and descending 

 small intestine, make two or three twists or turns around oneano- 

 ther; it is this portion which is enclosed by tbe basement-membrane 



Fig. 2B — Transverse sections ihr >ugh alimentary canal, a-e. 



of the crop and œsophagus, and forms the filter-chaniber. At the 

 anterior end of this chamber the small intestine bends posteriorly 

 and, after emerging IVom the {)osterior end of tbe flltei'-cbamljer, 

 runs soniewhat convoluted and alongside or pai'tly above the crop 

 — on the right hand side and accompanied by the urinary tubes — 

 to the large llask-shaped rectum (rec). The usually idose blind ends 



