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THE AMERICAN NATURALIST [Vol. XLIII 



of the body or in the neighborhood of the suckers, and are 

 variously interpreted as sticky or mucous glands or as 

 irritants to increase the flow of the juices which serve as 

 the food of the worm. They do not extend over the whole 

 body or any large part of it, and are not the subcuticular 



cells, nor are they so considered by any authors who have 

 studied them. They also differ markedly in shape from 

 the subcuticular cells, being more or less pear-shaped and 

 regular in outline, each cell having a distinct and single 



duct of large size. The subcuticular cells, on the other 

 hand, are often irregular in shape, often anastomosing 

 with one another and in many cases having the appear- 

 ance of parenchyma cells. They also show no ducts at all, 



