170 



ZOOLOGY. 



while the male is unknown. The worm li\'cs in the con- 

 nective tissue vtndei- the skin, especially of the extremities. 

 As the body of the female is full of young, the worm has to 

 he carefully and slowly extricated, so as not to be broken and 

 cause the embryos to be scattered under the skin of the host. 

 Carter regards a small worm ( Urolahes paludris) frequent iu 

 brackish water, as the immature form of the Guinea-worm. 

 It is also believed that the embryos enter the bodies of water- 

 fleas (Cyclops, etc.), and there moult, and that consequently 

 they may bo introduced into the body by drinking standing 

 water ; but this has not been proved. Other species live in the 

 peritoneum of the horse and apes, and an immature species 

 {Filaria lentlH) has been found in the lens of the liumau 

 eye. Filaria sangxtinis-lioininis is a worm of microscojoic 

 size found living in the blood of the mosquito in India and 

 China. It is said that the eggs are swallowed in the water 

 drunk by man, are hatched in his intestines, and obstruct 

 the smaller blood-vessels, causing, it is claimed, various 

 forms of elephantoid disease, jierhaps even leprosy. The 

 mosquito sucks ujj the parasite in the blood of leprous pa- 

 tients, voiding the eggs in the pools it frequents. Filaria 

 fiemaiica has occurred in the blood of the foetus of a dog 

 whose heart was filled with them. Grains of wheat are 

 often infested by a minute Nematode {Tylenchus scandens 



Schneider, Anguil- 

 lula tritici of Need- 

 ham. Pig. 118). 

 Other species live iu 

 flowers, moist earth, 

 and sour decaying 

 substances. Anguil- 

 lula aceti Eliren- 

 berg is from one to 

 two millimetres iu 

 length, and lives iu 

 vinegar. 



The genus Chmto- 

 sonia lives free iu 

 the sea, and has a broad swollen head beset with fine hairs. 

 It apparently connects the true Nematodes with Sagitta. 



Fig. 118.— Young Wlieat Worm, greatly maguifled. 

 c, section of a gram exhibiting !^ome worms and multi- 

 tudes ol eggs, magnifled ; b, an egg containing a worm 

 ready to hatch.— From Curtis, after Bauer. 



