DEVELOPMENT OF THE ASCARIDIXA 



A — PuJtsaiuruK nmbiguuit. B — "0.ri/uri»" brer-icnudn showing emer- 

 gence area and embryo in outline after inculmtinn for 64 hours at 22° 

 C. C-il — Aitpictiluris tetraptera (C — EgK incubated in water 24 hours; 

 D — 43 hours; E — 08 hours; F — Larva from intestine 4 hours after feed- 

 ing; G— Larva from cecum 4 hours after feeding; H — After 18 hours; 

 I — After 44 hours; J-K — 10 days after feeding; J, male. K. female; 

 L-M — 18 day*; after feeding. L. female. M. male). N-Q — Supfiarin 

 obvelata (N — Uterine egg containing mature emt>ryo ; O — Hatched em- 

 brj"o; P — Youngest larva found in cecum ; Q — Male measuring .8 1 

 mm.). R — EnierohiuM vermiculariM, larva three days after hatdiing in 

 Ringer's solution. S-T — Derma toxi/s vpUgern (S — Head. T- — ^Head. 

 fourth stage). U — Probstmayria riripara, lateral view of female am- 

 taining a well developed embr>'o. a second less developed and two eggs. 

 V-Y — Aficaridia gaUi ( V — cephalic extremity of second stage larva 

 showing oral prominence; W — Second stage, newly hatched; X — Tail of 

 third stage female showing preanal swelling; Y — Tail of fourth stage 



male). Z-CC — Ancurin himbrwoides (Z — Second stage (newly 



hatched); AA — Third stage; BB — Fourth stage (21 days); CC — Fifth 

 stage (29 days old). I)I>-EE — Cosmocercoides dukae (DD — Newly 

 hatched larva;' EE — Infective larva). FF-II — Contracaecum aduncuni 

 (FF-GG — Hatched larvae; HH — Anterior end of larva armed with 

 boring tooth; I1-— Larva from body cavity of Ascartui bifilonu). JJ — 

 Subulura brt/wpti, encysted infective larva recovered from body cavity 

 of the beetle Alphitobtufi diaperinus. KK — Hetarakis guUinae, infec 

 tive larva found newlv hatched in the small intestine. A-R. after Phil- 

 pot. J. Helminth., v. 2 (5), pp. 239-252. S-T. after Dikmans. 1931. 

 Trans. Amer. ilic. Soc. v. 50 (4). U, after Ransom, 1907, Trans. 

 Amer. Mic. Soc. v. 27. V-Y, after Roberts. 19^7. Bull. 2 An. H. Sta. 

 Queensland. Z-CC. after Roberts. 1934, Bull. 1. An. H. Sta. Queens- 

 land. DD-EE. after Harwood. 1930, J. Parasit. 17. FF-II, after 

 Markowski, 1937, Hull. Acad. Polon. Ser. B. J.7. after Alicata, 1939. 

 J. Parasit. 25. KK, after Ctapham, 1933, J. Helminth, v. 11 (2). 



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