PRESERJ\iTION AND EXAMINATION OF HELMINTHS 321 



Worm 



F. loa 



F. medinensis 



T. saginata ... 



T. solium 



T. echinococ- 

 ciis 



'J'rematodes, 

 both Fascio- 

 lidge and 

 Paramphis- 

 tomidae 



Schistomidte 



Leave Man 



By Chrysops dim- 

 idiata 



Embryos dischar- 

 ged into water 



Oncospheres 



Oncospheres 



"Hydatid cysts." 

 Does not leave 

 man, who is an 

 accidental host 



Eggs with unde- 

 veloped ovum 

 in feces, or in 

 one instance in 

 sputum 



Eggs with unde- 

 veloped ciliated 

 embryo, mira- 

 cidium, with 

 urine or feces 



Life outside Man 



Similar development in 

 salivary glands of 

 Chrysops 



Embryos swallowed ? by 

 chrysops and there 

 develop to a certain 

 extent 



In muscle of cattle (Cys- 

 ticercus bovis) 



In muscle of pig (Cys- 

 ticercus celluloste) 



Adult worm in intestines 

 of dogs, &c., who derive 

 infection from food, 

 offal from slaughter- 

 houses, &c. 



Ovum develops in water, 

 embryo enters molluscs 

 or fish and there multi- 

 plies asexually, produ- 

 cing ultimately young 

 flukes, cercariie, encys- 

 ted on vegetables or 

 free swimming in water 



Embryos escape from egg 

 when urine or fasces 

 are diluted. Further 

 development, if any, 

 outside man, is un- 

 known 



Re-enter Man 



Cyclops containing devel- 

 oped larvat swallowed 

 by man 



Eating beef containing 

 Cysticercus bovis 



Eating pork containing 

 Cysticercus cellulosa" 



By swallowing oncosph- 

 eres from fteces of 

 infected dogs 



Swallowed by man on 

 vegetables or in water 

 or in undercooked fish 



Probably enters through 

 the skin during bathing 



THE PRESERVATION AND EXAMINATION OF 

 HELMINTHS. (After Daniels.) 



SMALL NEMATODES. 



Preservation. 



(i) Shake up the live worms in a i per cent, salt solution, to remove 

 mucus. 



(2) Kill by dropping into boiling 70 per cent, spirit and allow to 

 cool. 



(3) Transfer to fresh 70 per cent, spirit for storage. 



For Clearing and Mounting. 



(i) After treating with stages i and 2 as above, transfer to a mixture 

 composed of 70 per cent, spirit, 95 parts with 5 parts of pure glycerine. 



(2) Evaporate in a water or paraffin batli until all the alcohol has 

 gone. 



(3) Mount in glycerin jell v. 



(4) Ring with gold size. 



Examination without Mounting. 



(i) Take from the 70 per cent, spirit and place in methylated 

 spirit. 



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