EEL-TRAP HAIRS 213 



body is ensured, not by the presence of a thick outer wall which 

 would have been the simplest arrangement but by the turgescence 

 of a thin-walled tube, stiffened at intervals by transverse buttresses 

 in the shape of cross-walls. In this way the hairs are enabled to 

 collapse, after they have performed their temporary function, and thus 

 to leave the way open for the escape of the pollen-covered insects. 



