337 



less in the cases described in Alexandria, Egypt. 

 It is possible that they are not the same diseases, 

 and the subject requires elucidation. In the Mon- 

 tana disease, piriform, ring-shaped, and cocci-like 

 forms occur. 



6. Piroplasma equi (Laveran). — Found in 

 horses in South Africa. 



Ticks 



Life History. — The female, after satiating her- 

 self with blood, falls to the ground and, in a few 

 days or weeks, lays eggs. 



Eggs. — The eggs are laid in masses of several 

 thousands (Ixodidae), of some hundreds (Argasidae). 

 The process lasts about a week. They are small, 

 oval, opaque bodies. They may take weeks or 

 months to hatch out. From the eggs is developed — 



The Larva. — These are hexapod. They cling 

 to blades of grass, etc., and may do so for several 

 months before attacking a host. The larval stage 

 lasts six to ten days. The moult then takes place, 

 and there emerges from the skin — 



The Nymph. — These are octopod. They re- 

 semble adult females. They have respiratory 

 stigmata, but no sexual organs. The nymphal stage 

 lasts seven to ten days. The nymph moults, and 

 there emerges — 



The Adult. — These again attach themselves 

 to the host, and in a few days copulation takes 

 place. The female gradually distends and remains 

 attached for about nine to eleven days. The female 

 then drops off. What the male does is uncertain. 

 The female's whole cycle on the host is thus 

 twenty-two to thirty-one days. The entire life 

 cycle takes, probably, about two to three months. 



X 



