1019.] 



93 



{m.g.), which forms a straight tube, narroAving slightly posteriorly, and 

 ending in the posterior part of the body. From the anterior portion of 

 the mid-gut, close to the proventriculus, arise two very long lateral 

 caeca (a.c.) which run backwards and are closely apposed to both sides 

 of the mid-gut. The surfaces of these caeca show a series of deep trans- 

 verse folds. Two other lateral caeca arise from the posterior portion of 

 the mid-gut, some distance in front of the Malpighian tubes. These 



Fig. 1.— Alimentary canal of the larva of Scatopse notata -. Oe., oesophagus 

 Pc, proventriculus ; a.c, anterior lateral caeca : m.g., mid-gut ; p.c, posterior 

 caeca ; M,, Malpighian tubes ; h.g., hind-gut. 



posterior lateral caeca (2).c.) are directed forwards and are not fixed to 

 the mid-gut along their lateral borders ; the}' are shorter than the 

 anterior caeca, and also show the transverse folds, especially in their 

 basal portions. 



The four strongly-pigmented Malpighian tubes (M.) arise sepa- 

 rately at the junction of the mid- and hind-gut. The latter (h.ff.), 

 after making a short bend forward and then backward, ends in the anus. 



