220 



THE MORPHOLOGY OF THE COMMON CRAYFISH. 



processes, and the disposition of the vascular canals in its 

 interior gives it the appearance of being radially striated. 

 The set?e, so abundant in the adult, are ver}^ scant}^ in 

 the newly hatched young ; and the great majority of those 

 which exist are simple conical prolongations of the un- 



''='"=^. 



Fig. 60. — Astacus ^//iv'<if?7/A\— Newly-liatched young ( x 6). 



calcified cuticle, the bases of which are not sunk in pits 

 and which are devoid of lateral scales or processes. 



The young animals are firmly attached to the ab- 

 dominal appendages of the parent in the manner already 

 described. They are very sluggish, though they move 

 when touched ; and at this period they do not feed, but 



