Introduction. xxi 



Nemertina None, 



Nematoda Many species occur as parasites in the alimentary canal 



(Ascarids and Ankylostomiivi), in the blood system and 

 connective tissues {Filarix), and cause disease (Elephan- 

 tiasis) ; the Guinea worm (Filaria mcdinensis) ; TrichinOr 

 spiralis. 



Chsetopoda Land leeches [Hxmadispa ccylonica) attack man in 



Ceylon and India and elsewhere. 



Crustacea Crabs and lobsters bite, also land-crabs (Gccarcinidas). 



Arachnida A few spiders (Mygalc) have poisonous bites; mites {Sar- 



coptidaa) produce itch, etc., and the sting of scorpions 

 is poisonous. 



Chilopoda Centipedes (ScotojJC7icZra gigantca, S. 7)wrsita)is) in tropical 



climates are poisonous, and produce painful wounds. 



Diplopoda None. 



Hexapoda Insects of the orders Diptera (flies) and Hemiptera- 



Heteroptera (bugs) bite in all parts of the world. 

 Biting Diptera include :— mosquitoes (Cidicidie), sand- 

 flies {Sirmdidee), gadflies (Tabanidx), stinging-flies 

 [Chnjsops, Stcntioxys), tsetse-flies (Glossina). Diptera 

 also live as parasites in their adult stage (jigger-flea) and 

 in the larval state in man (Dermatobia, Screw-worm). 

 Bugs of the genera Cimex and Conorhiiins. 



Mollusca The bites of some are poisonous (Cuntisa aulicus in 



Moluccas, C. tcxtilis in South Sea Islands, and most 

 other Toxiglossa), 



Tunicata None. 



Fish Sharks and various poisonous fish, the latter (i) poisonous 



as food, Cliipea thrissa, C. vcncnosa ; species of Scants, 

 Tetrodon, Diodon, ^alistcs, Ostracioii ; the roes of 

 barbel, pike and burbot, and (ii) on account of the 

 poisonous wounds they may produce — weavers (Tra- 

 chinus), stinging rays (Trygonidx), species of Synanccia 

 and Thalassophryne. 



Amphibia None. 



Reptilia Many snakes are poisonous (rattlesnake, cobra, fer de 



lance, blue adder, pufi adder, purple and short death 

 adders) and a single lizard (the Heloderma). Crocodiles 

 and alligators may devour man (the gavial, Gavialis 

 gangetictis, Crocodilus vulgaris). 



Birds None. 



Mammals Most of the large carnivora (lions, tigers, bears, wolves) 



may cause bodily injury to man and often devour him. 

 Any large mammals such as rhinoceros, elephant, deer, 

 may attack and injure him. 



Survey of Sub-group (])) of Group D. 

 animals which cause disease by acting as germ carriers. 



Protozoa to Crustacea None. 



Arachnida Probably ticks (Ixodidx) may distribute disease from 



animals to man. 



Chilopoda and Diplopoda None. 



Hexapoda All piercing-mouthed insects may either carry disease 



direct from man to man or animals to man gadflies 

 (Tabanidx), Stomoxys and tsetse-fly {Muscidse), sand- 

 flies (Simulidse) ; bugs [Cimex a.nA. Conorhinus) ; or they 

 may act as intermediate hosts of parasites (mosquitoes 

 and malaria and filariasis). Germs may also be carried 

 to food and drink by dung-feeding flies {Musca, Calli- 

 phora, Scatqphaga) from latrines and foul matter 

 (typhoid). 



