TOXASCARIS 465 



therefore conjectured that there must be an intermediary host, and 

 v. Linstow thought he had found it in myriapods (Jnlus guttulatus). 

 Subsequently, Davaine's opinion proved correct. First of all Grassi 

 succeeded in infecting himself by swallowing 100 embryo-containing 

 eggs of Ascaris lumbricoides ; five weeks after ingestion the worms had 

 attained maturity and their ova appeared in the faeces. Calandruccio 

 also sought to infect himself, but failed, yet he succeeded in infecting 

 a little boy aged 7. Lutz also reports a successful experiment which 

 must have been positive, as young worms 5*5 to 18 mm. long were 

 expelled. Lutz proved that the eggs lost their albuminous shell by 

 long lying in water and then died when introduced into the stomach ; 

 this would explain the failure of Leuckart's experiment ; in moist earth 

 the albuminous shell is retained. Finally, Epstein conducted unim- 

 peachable experiments on three children which place direct infec- 

 tion with embryo-containing eggs beyond doubt; he, moreover, 

 proved that the development of the eggs takes place more rapidly in 

 the faeces when there is free admission of air, sun, and a sufficiency 

 of moisture. 



Accordingly, infection occurs partly through water, but principally 

 direct from the soil. 



Ascaris, sp. 



Wellmann states that yet another species of Ascaris in man occurs 

 in the highlands of Angola : up to the present nothing certain 

 is known about it (Welland, " Critical Notes on Tropical Diseases 

 of the Angola Highlands," New York Med. Journ. and Philadelphia 

 Med. Journ., August 12 to September 2, 1905.) 



Ascaris texana, Smith et Goeth, 1914. 



Female alone known ; 58 to 60 mm. and upwards in length ; 

 characterized by the serration of the anterior border of the lip and by 

 the appearance of interlabia. Evacuated by a white settler in Texas. 

 Position of this worm doubtful. 



Ascaris maritima, Leuckart, 1876. 



Only one immature specimen, a female (43 mm. in length and 

 i mm. in breadth), has hitherto been described, and it was vomited by 

 a child in North Greenland in 1865. (R. Leuckart, " Die menschlichen 

 Parasiten," 1876, edition 2, i, p. 877.) 



Genus. Toxascaris (rogov, an arrow), Leiper, 1907. 



Body anteriorly bent dorsally, cuticle finely striated. (Esophagus 

 without a distinct bulb. Tail of male tapers to a point. Testis in 

 anterior portion of posterior half of body. Vulva about middle of 

 body. Eggs oval and smooth. 



