820 Proceedings of Royal Society of Edinburgh. [sess. 
corpuscles noticed in the blood, that the ill-health of the miners 
was traced to its proper source. As the high temperature and 
humidity of the Cornwall tin mines are extremely favourable to 
the development of the larvae of Ankylostoma duodenale , and 
as the mines have become infected through the irregular disposal 
of the excreta of the workmen, pails are now provided underground 
for the use of the miners. These pails are taken to the surface 
daily, rinsed with boiling water and disinfected. 
Anatomy and Physiology of the Miners ’ Worm. 
The Anhylostoma duodenale is one of the helminthozoa of the 
nematode class, and is included under the head of the Uncinaria, 
lienee the occasional substitution by some writers of the word 
uncinaria for ankylostoma. There is an ankylostomiasis not 
only of man, but of the dog, wolf, fox, and sheep ; and there is a 
form described by Stiles as the American uncinaria. It is only 
the Ankylostoma duodenale and the American uncinaria that 
attack man. Although several attempts have been made to 
introduce the other forms of ankylostoma into man, they have 
failed. There is apparently no intercommunicability between the 
various types of the parasite. When examined in the fresh state, 
the fully-developed worm of man is seen as a slightly blunted fili- 
form body, white or greyish- white in colour, or rose- white if it 
contains blood. There are male and female ankylostomes. The 
males are slightly shorter than the females ; the males measure 8- 
11 millimetres, f to fully J inch in length, and the females 18 
millimetres, or about f of an inch. They are about J a millimetre 
or of an inch in breadth. Probably the size of the worm varies 
in different countries. The males are not only shorter in length 
than the females, they are less numerous, the proportion being 
one male to three females. The tail end of the male swells out 
into an umbrella-shaped expansion which is the genital sac, whereas 
the tail of the female ends in a very fine point. The worms 
have an external covering or cuticle composed of two layers. The 
alimentary canal, commencing at the buccal cavity, leads into the 
oesophagus, a well-developed muscular tube, which is guarded, 
according to Brian^on, by valve-like structures, to prevent the 
