:\IETASTRONGYLIX.E ^.57 



The worm is parasitic in the respiratory organs of the sheep, goat, 

 camel, and deer. 



2. Synthetocaulus rufescens (Strongylus rufescens). Fig. 131. 

 INIetastrongyHnse (p. 256).— The body is thin and hair-hke, brownish 

 red in color. The mouth has three papilliform lips. The bursa of the 

 male is notched in front and has two small lateral indentations. The 

 spicules are striped transversely and rounded at their ends. The poste- 

 rior extremity of the female terminates in a blunt point; vulva imme- 

 diately in front of the anus at the base of a small pre-anal elevation. 



B 



Fig. 130. — Dictyocaulus filaria: a, female; b, male, 

 natural size; c, anterior extremitj-; d, eggs, — enlarged. 



Length of female, 25-35 nun. (5/8-1 3/8 inches) ; male, 18-28 mm. 

 (3/4-1 1/2 inches). 



The eggs are oval, 75-120 microns in length by 45-82 microns in 

 breadth. Segmentation has advanced at the time they are deposited, 

 after which the embryos develop rapidly and are liberated in the pul- 

 monary alveoli. From the alveoli the}' pass to the bronchi and trachea 

 from whence they are expelled to the outside where they have a strong 

 vitalitj' and are capable of resisting desiccation for a long time. 



As found in the trachea and larger bronchi, the embryos measure 

 300-400 microns in length by 16-18 microns in breadth. 



The worm is parasitic in the respiratory organs of the sheep, goat, and 

 rabbit. 



