ANKYLOSTOMA (MINERS’ WORM). 295 
But if the eggs cannot hatch in certain parts which are too cool, the 
larve can be brought to these parts either on the boots, &c., or by the 
flow of water. 
There is no evidence to show that any substance in the coal is dele- 
terious to the worm, though weathered coal might contain such products. 
Tf the water is salt (as it is at Levant Mine) protection seems to be 
secured ; but traces of the heavy metals (iron, copper) do not seem to be 
harmful. 
Nothing is known of any natural enemies. In some mines the fecal 
deposits, wood, &c., show an abundant fauna, most commonly dipterous 
larvee and small nematodes other than Ankylostoma. 
It might be supposed that in the case of a species in which a single 
female produces millions (probably many millions) of eggs some specific 
enemy would have been developed—some organism whose special charac- 
ters enabled it to live on the highly nutritious contents of the eggs, or 
on the newly hatched larve. But if such a hostile species has been 
evolved it is in the tropical and sub-tropical home of Ankylostoma that it 
should be sought for, not in the temperate zone. In the mud of a 
British coal-mine the limited number of species of animals and plants are 
either from the surface above, or have been brought with the timber from 
uninfected countries. It is possible, therefore, that in a warm and moist 
coal-mine in Great Britain the conditions are actually more favourable to 
the uncontested life of the larvee than even in the tropics. It would not be 
out of harmony with any known facts to suppose that a single pair of 
worms might give rise in one generation to a progeny equal in number 
to the population of the British Islands. 
(C) Preventive Measures. 
(a) In non-infected mines. 
1. A sufficient supply of sanitary pails, combined with a rigid system 
of inspection and cleaning, is all that is necessary if the use of these con- 
veniences can be enforced. The habit of defecating underground at all 
should be discouraged as much as possible : much may be done in this way 
by providing proper and well-looked-after accommodation at the pit’s 
mouth. In dry mines the feces can probably be safely disposed of by 
burying them under coal dust in the goaf; but in all cases permanent 
roads and stations should be provided with conveniences. 
2, Examination of fresh hands. All men applying for work who have 
ever worked in tropical or South European countries, or in mines where 
the worm is known to be present, should be rejected till it is shown that 
they do not harbour the worm. It is useless doing this unless their state 
of health is entirely disregarded ; it is of no moment whether they are or 
have been ill or not, since perfectly healthy persons may carry the worm 
and be capable of infecting a mine. Some sort of quarantine list should 
be made. At the present it would include Cornwall, Westphalia, 
the French and Belgian coalfields, South European and all tropical 
countries. 
3. Reduction of temperature and moisture is difficult, in most cases 
quite impracticable, and not necessary if proper sanitary and quarantine 
regulations are made and carried out. Any reduction in the moisture is, 
moreover, not unattended with danger from explosions. 
There should be no difficulty in introducing a proper system of 
