VERMES 



l 2] 



Nematoda are of much general interest. There arc some whi< h 

 are parasitic on the roots of plants, where the young worms bore 

 their way into the roots, and the plant then tonus swellings or 

 galls about them and finally dies (Fig. 112). It is particularly 



Fn;. 112. Heterodera schachtii, a roundworm parasitic on the roots of turnips and other 

 garden and greenhouse plants. I, piece of a turnip root showing two fully developed 

 female worms, which have burst the epidermis of the root, to which they are attached by 

 their heads only; 2, a similar piece of turnip root showing three larva- just entering by 

 boring; 3, free-living male, fully developed; 4, fully developed female as in 1, mine highly 

 magnified, the posterior end of the body surrounded by a gelatinous substance containing 

 three developing eggs; 5, adult female with portion of body wall removed, showing egg- 

 tubes and saccular digestive apparatus. (Photographed from a Leuckart-Nitsc lie wall chart 

 by the author; permission of Dr. C. Chun.) 



