ASCARID.E 



277 



a shallow cleft and tripartite division. 3. The vulva of the female is 

 placed in the anterior third. 



The eggs of N. americanus are larger than those of A. duodenale. In hook- 

 worm disease we have ground itch, tibial ulcer, anaemia, interference with physical 

 and mental development and, in bad cases, dirt eating. 



Shade, moisture and sandy soil seem essential factors for the development of 

 hookworm. Prophylaxis is essentially one connected with soil pollution. The 



Ova or the Parasitic Worms or Man 

 NEMATODA 



SCALE. x ieoo 



A A 



ORAWN 



CrVMthout outer 

 envelope (Modt 



/roin Stiles. \<t<. an 



ArShowind / 

 sides syifi-f, 

 metrically H 

 convex [{ 



(after Loos 5.,3t 



over to 

 I show one 

 laid? flatten 



edloriginoi) 



Oxyuris 



vermiculorisA.B. 



Strongylus 

 subtilis 



s, 1995) 



Asccxris" Atfchvlostoma 



lumbricoides ^^^^ d^SSSSS/g.., 



A R f^ T\ Tr-i/^V-ii t-i t_* Looss'ws')" in fresh stool 



rrichuris Strongvloides 



trichium ste'rcomlis 



(OriginAl x^bJ^LnjJiSUS 



w: Embryo 

 M in stool 

 after 12 to46 

 , -- . hours. 



Agchylostoma 

 duodenale 



.MKHjt, 



IOOS) 



FIG- 76. ^Nematode ova. 



subjection of the faeces to some septic tank process is more reliable than chemical 

 disinfection or burying the faeces 8 to 10 inches under ground. 



These have three papillae around oral cavity, one dorsal and two 

 ventral. The male has two equal-length spicules. An intermediary 

 host is not needed in the life history of this family. 



Ascaris Lumbricoides. The male round or eel worm is from 5 to 



