498 



ZOOLOGY 



ph 



SECT. 



The pharynx com- 

 municates by a very 

 small aperture with 

 the second and largest 

 division of the enteric 

 canal, the huge crop 

 (cr.), a thin - walled 

 tube extending from 

 the eighth to the 

 eighteenth segment, 

 and produced into 

 eleven pairs of lateral 

 pouches (cr. 7, cr. 11), 

 the first ten of which 

 are directed outwards 

 and correspond each to 

 a segment, while the 

 eleventh (cr. 11) passes 

 directly backwards as 

 far as the twenty- 

 fourth segment. The 

 lumen is divided be- 

 tween the pairs of 

 pouches by transverse 

 septa, perforated by 

 central apertures, into 

 eleven chambers. The 

 crop is capable of great 

 dilatation, and its form 

 varies greatly accord- 

 ing to whether it is 

 empty or gorged with 

 blood. Posteriorly the 

 crop communicates by 

 a minute aperture with 

 the stomach (st.), a 

 tubular chamber with 

 a dilated anterior end, 

 and having its wall 

 produced internally 

 into a spiral fold : this 

 is the digestive portion 

 of the canal ; the blood 

 is passed into it from 

 the crop with extreme 

 slowness, and under- 

 goes an immediate 

 change, its colour turn- 



