APPENDIX I. 



THE PREVENTION AND TREATMENT OF VERMICEODS DISEASES. 



Although we have said in chapter v. that some worms (Angnil- 

 lulidis) occasion considerable harm to certain crops, yet it is 

 amongst our stools that their ravages are mostly felt, especially 

 in sheep, cattle, and horses. As the loss that many worms are 

 accountable for often reaches very serious dimensions, a few general 

 notes on the prevention and treatment of these parasitic diseases 

 may not be out of place here, after having dealt with their economic 

 history in preceding chapters. The three most important groups of 

 the parasitic worms are the Tapeworms, Round- or Thread-worms, 

 and Flukes. Tapeworms often cause severe diseases in animals 

 and man (so called Tcemosis). When we know the life-history of 

 a species it is usually easy to prevent the increase, if the trouble 

 is taken to do so ; but where we are ignorant of the various stages 

 and habitats of the pests, remedies only lie in our power. As 

 pointed out in chapter iv., most tapeworms have two distinct hosts 

 — one in which the adult sexual tapeworm lives in the intestines, 

 another in which the asexual cyst or bladder-worm takes up its 

 abode. The cysts are usually found in carnivorous and omnivorous 

 animals, in the various organs and internal membranes. Each cyst 

 may give rise to one or hundreds of adult worms, in another animal, 

 on being eaten. By the destruction of these cystic parts the tape- 

 worm stage is prevented, and the tseniosis is stopped from spread- 

 ing. For instance, if all the heads of " pothery " or " sturdy '' sheep 

 are destroyed (and sometimes in lumbar-gid the spinal cord) with 

 the coenuri in them, so many hundreds of Toenia ccenurus, one of the 

 dog tapeworms, are destroyed. Again, if the diseased pork called 

 " measly pork " is not eaten insufficiently cooked by human beings, 

 the dreaded human tapeworm, T. solium, is prevented, and the same 

 with " measly " beef. 



