Introduction. 
xxi 
Nemertina 
Nematoda , 
Chsetopoda 
Crustacea 
Arachnida . 
Chilopoda 
Diplopoda 
Hexapoda 
Mollusca 
Tunicata 
Fish .... 
Amphibia 
Reptilia .. 
Birds 
Mammals 
Many species occur as parasites in the alimentary canal 
( Ascarids and Ankylostomum), in the blood system and 
connective tissues ( Filarix ), and cause disease (Elephan- 
tiasis) ; the Guinea worm ( Filaria medinensis ) ; Trichina 
spiralis. 
Land leeches {Hxmadispa ccylonica) attack man m 
Ceylon and India and elsewhere. 
Crabs and lobsters bite, also land-crabs (Gecarcinidx). 
A few spiders ( Mygale ) have poisonous bites; mites ( Sai - 
coptidx) produce itch, etc., and the sting of scorpions 
is poisonous. 
Centipedes ( Scolopcndra gigantea, S. morsitans ) in tropical 
climates are poisonous, and produce painful wounds. 
None. 
Insects of the orders Diptera (flies) and Hemiptera- 
Heteroptera (bugs) bite in all parts of the world. 
Biting Diptera include: — mosquitoes {Culicidx), sand- 
flies ( Simulidx ), gadflies ( Tabanidx ), stinging-flies 
(Chrysops, Stomoxys ), 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 Conorhinus. 
The bites of some are poisonous ( Conusa aulicus in 
Moluccas, G. textilis in South Sea Islands, and most 
other Toxiglossa). 
None. 
Sharks and various poisonous fish, the latter (i) poisonous 
as food, Clupea thrissa, C. vcnenosa ; species of Scartts, 
Tetrodon, Diodon, Balistcs, Ostracion ; 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 Synanceia 
and Thalassophrync. 
None. 
Many snakes are poisonous (rattlesnake, cobra, fer de 
lance, blue adder, puff adder, purple and short death 
adders) and a single lizard (the Hcloderma). Crocodiles 
and alligators may devour man (the gavial, Gavialis 
gangeticus, Crococlilus vulgaris). 
None. 
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 ( b ) of Group D. 
ANIMALS WHICH CAUSE DISEASE BY ACTING AS GERM CARRIERS. 
Protozoa to Crustacea 
Arachnida 
Chilopoda and Diplopoda 
Hexapoda 
None. 
Probably ticks ( Ixodulx ) may distribute disease from 
animals to man. 
None. 
All piercing-mouthed insects may either carry disease 
direct from man to man or animals to man gadflies 
{Tahanidx), Stomoxys and tsetse-fly ( Muscidx ), sand- 
flies ( Simulidx ) ; bugs {Cimex and 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, Scatophaga) from latrines and foul matter 
(typhoid). 
