278 j THE ANIMAL PARASITES OF MAN 



and these he likewise handed over to Bavay. The latter recognised another 

 species, and described it as Anguillula intestinalis . Both forms were then 

 regarded as the cause of Cochin China diarrhoea, until, in 1882, Leuckart 

 was able to demonstrate that the two forms are only two succeeding 

 generations of the same species, of which the one (A. intestinalis} lives 

 parasitically in the intestine, whereas its young (A. stercoralis) attain the 

 open, where they come to maturity and propagate. The young of these 

 live a*gain parasitically. There thus exists the same heterogony as was 

 discovered by Leuckart in Rhabdonema nigrovenosum of frogs, which 

 heterogony indeed, according to v. Linstow, appertains to the entire family 

 of the Angiostomidae* 



(1) The parasitical generation (Anguillula intestinalis} measures 

 2*2 mm. in length, and 0*034 mm. in breadth ; the cuticle is 

 finely transversely striated ; the mouth is surrounded by four 

 lips ; the oesophagus is almost cylindrical and a quarter the 

 length of the entire body. The anus opens shortly in front of the 

 pointed posterior extremity ; the female genital orifice is situated 

 in the posterior third of the body ; the eggs measure 0*050 

 0*058 mm. in length, and 0*030 0*034 mm. in breadth. As 

 is the case in Rhabdonema nigrovenosum, Leuckart considers this 

 generation to be . hermaphroditic ; other authors (Rovelli) regard 

 it as consisting of females reproducing by parthenogenesis. 



(2) The free-living generation (Anguillula stercoralis) is certainly 

 sexually differentiated ; its body is smooth, cylindrical, somewhat 

 more slender at the anterior extremity and pointed at the tail 

 end. The mouth has four indistinct lips ; the oesophagus is short, 

 with a double (rhabditis-like) dilatation ; there are three little 

 teeth in the posterior dilatation ; the anus opens in front of the 

 tail end. The males measure 0*7 mm. in length, 0*035 mm - i n 

 breadth. They carry their posterior end rolled up ; the two 

 spicules are small and much curved. The females measure I mm. 

 in length or a little over ; 0*05 mm. in breadth. The tail-end 

 is straight and pointed ; the vulva lies somewhat behind the 

 middle of the body. The yellowish, thin-shelled ova measure 

 0*07 mm. in length, and 0*045 mm - i n breadth. 



As Askanazy has shown the form that lives parasitically bores 

 deeply into the mucous membrane of the intestine, and frequently 

 into the epithelium of Lieberkiihn's glands, both for nourishment 

 and oviposition. The eggs then develop in the intestinal wall. The 

 young, which are hatched out, and measure 0*2 mm. in length, again 

 reach the lumen of the intestine, 1 and grow to double or three times 



1 As a case published by Teissier testifies, they may also abnormally appear in 

 the circulatory system (Arch. mid. expr. et d'an. path., 1895, vii., p. 675). 



