384 THE ANIMAL PARASITES OF MAN 



from direct entry into the stomach but also, according to van Durme 

 and Looss, through the skin. 



Occurrence in Man.A.s already mentioned, Strongyloides stercoralis was 

 first observed in persons suffering from so-called Cochin China diarrhoea. 

 From the enormous numbers of parasites evacuated with the faeces, the cause 

 of the disease was apparently evident. It appeared, however, that only some of 

 the soldiers returning from Cochin China and Martinique, and suffering from 

 diarrhoea, harboured Strongyloides (Chauvin). Breton made the same observations 

 in Cochin China and found that only 10*4 per cent, of cases of chronic dysentery, 

 and 8'8 per cent, of chronic diarrhoea, show Strongyloides. Normand, moreover, 

 found that only a few of the Europeans residing in Cochin China are exempt 

 from S. intestinalis, yet the people exhibit no intestinal symptoms ; if, however, 

 from any cause a catarrhal condition of the intestine supervenes the condition 

 is changed, the parasites appear in larger numbers, and the disorder is 

 considerably intensified. 



S. intestinalis, besides being present in the Indo-China region, also occurs 

 in the Antilles, in Brazil, Africa, and Europe ; in 1878 it was discovered 

 in Italy by Grassi and C. and E. Parona ; in 1880 it was also found in the 

 labourers working at the St. Gothard tunnel. It was imported into Germany, 

 Belgium, and the Netherlands by Italian labourers. One sporadic case has been 

 observed in East Prussia, and the worm has also been reported from Siberia. 



In mammals the following species are found : Probstmayria (Strongyloides} 

 vivipara, Ransom, 1907, in Equus caballus ; Strongyloides fiilleborni,\. Linst., in 

 Anthropopithecus troglodytes and Cynocephalus babuin. 



Their development is, so far as is known, the same as that of Strongyloides 

 stercoralis (v. Linstow, CentralbL f. Bakt., Path. u. Infektionsk., 1905, Orig. xxxviii, 

 P- 532). 



Family. Gnathostomidae. 

 Genus. Gnathostoma, Owen, 1836. 



Syn, : Cheir acanthus, Diesing, 1839. 



Easily recognizable by the numerous spines which cover the entire body or 

 only the anterior extremity, and terminate in several points ; head globular and 

 beset with bristles ; mouth with two lips ; two spicules ; vulva situated behind the 

 middle of the body. 



Gnathostoma siamense, Levinsen, 1889. 



Syn. : Cheir acanthus siamense, Lev., 1889. 



Female measures 9 mm. in length, i mm. in breadth. There are 

 eight rows of simple spines on the head ; the armature of spines extends 

 over the anterior third of the body only ; each spine on the anterior 

 region of the body spreads into three points, of which the middle one 

 is the longest ; the posterior spines are simple ; they gradually become 

 smaller and then disappear entirely. The vulva is situated behind 

 the middle of the body. 



Male. 1 0*5 mm. long by 0*6 mm. broad. Head terminates in a 



