TRICHOSTRONGYLINyE 



433 



has a recurved, hook-like process; the vulva is close in front of the 

 anus. The eggs are elliptical, 57^ to 100 p, in length, 39 //, to 72 yu, in 

 breadth ; when the eggs are deposited the embryo is already formed, 



220 yU, tO 350 yLt by IQyLfc to I2//,. 



Metastrongylus apri frequently lives in the bronchial tubes usually 

 the smaller ones of the pig 1 and wild boar ; it is also found occa- 

 sionally in sheep and in man ; in young pigs it is apt to set up 

 a bronchitis, which frequently causes death. 



The first communication as to the occurrence of this species in 

 man was that of Diesing, who, in 1845, * n Klausenburg, had the 

 opportunity of examining Strongylidce found by Jortsits in the lung 

 of a little boy, aged 6, in Transylvania; probably also the Nema- 

 todes found in the trachea and 

 larynx of man, and described by 

 Rainey and Bristowe as specimens 

 of Filaria tracliealis, belong to 

 this group ; according to Chatin, 

 Metastrongylus apri may also occur 

 in the intestine of man ; this oc- 

 currence, however, may in all 

 probability have been due to an 

 accidental introduction of adult 

 worms into the intestine, and 

 should not be attributed to an 

 infection by the larval stage. 



No experiments to induce in- 



/ j- i . . . riG. 308. Metastrongylus apn : one side 



tectlOll have been made ; it IS prOD- of bursa. a., anterior ; a.*., antero-external ; 

 able, however, that infection is a ' m -> antero-median ; /.;/;., postero-median ; 



direct and without the aid of an 

 intermediate host. 



A 



postero- external ; /. , one division of 

 posterior ray. (Stephens.) 



Sub-family. Trichostrongylinae, Leiper, 1908. 



Strongylidae with buccal capsule absent or slightly developed, 

 vagina short, uteri divergent (i.e., anterior and posterior), ovejectors 

 differentiated. Parasitic in the alimentary canal. Contains the 

 genera Trichostrongylus, Haemonchus, Ostertagia, Nematodirus, 

 Cooperia, Uictyocaulus. 2 



1 The reports of the city inspection of meat in Berlin state that Strongylidce in the lungs 

 of pigs are by no means rare; therefore the lungs of 1,941 pigs were condemned between 

 18851886, of 1,641 between 18861887, of 3,237 between 18871888, of 4,855 between 

 18881889, of 7,197 between 18891890, and of 5,574 pigs between 18901891, etc. 

 Ostertag found Strongylus apri in 60 per cent, of the pigs examined in the Berlin abattoir ; 

 Meyer, in Leipzig, found the parasite in 15 per cent, of the native pigs and in 52 per cent, of 

 the Hungarian pigs. 



2 Dictyo:auhis is parasitic in the bronchi. 



