INDEX. 325 



Peat, formation of, 241 

 Peewits beating the ground, 28 

 Percolation of earth into the chalk, 300 

 Perichseta, naturalized near Nice, 108 

 Perrier, worms surviving long immersion, 13 



on the calciferous glands, 45 



on the action of the pharynx, 58 



on the burrowing power of worms, 101 



on naturalized worms, 108 



on worms killed by acetic acid, 162 



on the gizzards of worms, 249, 252 



Petioles of Clematis, 80 



of the ash, 81 



Pharynx, action of, 58 



Pike, stupidity of, 96 



Pine-leaves used in plugging up burrows, 61, 73 



lining burrows, 114 



Pipes, formation of, in the chalk, 139 

 Playfair on Denudation, 293 

 Ploughed fields, old, 295 

 Plugging up of the burrows, 60 



use of the process, 64 



Prehension, power of, by worms, 58 



Qualities, mental, of worms, 34 



Eamsay, Mr., on the sinking of a pavement undermined by 

 worms, 194 



on Denudation, 233 



Eemains, ancient, buried by worms, 178 



Ehododendron leaves, 71 



Kichthofen on dust deposits in China, 239 



Robinia, petioles of, 83 



Rocks, disintegration of, aided by worms, 238 



triturated in the gizzards of worms, 252 



