Porcupine 



615 



tail are offensive, for the latter is thrashed about vigorously at 

 a foe, and the daggers, being loosely attached, are driven into the 

 enemy's flesh to rankle and sink, and defy all efforts to remove 

 them. 



Through the courtesy of the Geological Survey at Ottawa 

 I recently had the opportunity to make an enlarged drawing 

 of a representative quill (Fig. 173). The specimen was taken 



Fig. 173 — Quill from back of Porcupine; magnified 14 diameters. A, point; B, root or bulb. 



from the back of a stuffed Porcupine {E. dorsatum). I expected 

 to find those of the tail more highly specialized, but was dis- 

 appointed. Examples from head, back, and tail differed 

 chiefly in size. 



The extreme point is polished and keen; speedily the 

 barbs begin to show. I reckoned up a round thousand on this 

 specimen. They die away on the shoulder of the quill. 

 When soaked in warm water they stick out much more, so we 

 may believe that they also flare out when in the warm flesh of 

 the victim. 



The barrel is smooth and highly polished. The bulb 

 presented no special features. 



How are these daggers used .? The creature does not curl defence 

 up into a many-rayed globe — hedgehog or globe-fish fashion — 

 as some seem to think. I have tried many times to make it do 



