and depart again in search of another. Rodent burrows, grass roots, 



or spaces under cow dung or stones are not chosen in preference to 

 cracks in soil or under grass bedding. Oviposition commences from 



ten to foTirteen days after leaving the host. 



To observe the effect of the environment of niches in various 

 biotopes on oviposition and the life cycle, engorged females were 

 placed in each conceivable type of situation (in test tubes 10 cm. 

 long, 2 to 3 cm. in diameter; into one end four reeds 10 cm. in 

 length were placed and cheesecloth wrapped around them, the oppo- 

 site end plugged with cotton; cheesecloth end placed down). 



1. Northern slopes of hills, without roots, i.e. ploughed 

 or overgrazed, no wild or cultivated vegetation; where untouched 

 a variety of vegetation persists (scientific names given) . Two 

 tubes containing engorged females were placed in cracks in soil, 

 two in "insect nests," one in a rodent burrow, four under grass 

 roots, and two under a cake or cow dung. 



2. Southern slopes of hills, which are considerably steeper 

 than northena slopes and covered by a thinner layer of loess but 

 with more vegetation near the summit; little cultivated or not at 

 all; annual grasses with many xerophilic perennials; almost no 

 cracks in soil, rodent burrows, or "insect nests". Here the only 

 place in which a female may hide is in shallow interstices of an- 

 nual grass roots; three tubes were placed in this situation. 



The remainder of the experiment was undertaken in an irri- 

 gated part of the valley, a weakly undulating plain of river 

 deposits and mostly under cultivation. 



3. Motmtain steppe (in lower part of valley); neglected weed 

 patches of different age. The only hiding places for ticks are 



in cracks in soil and xmder grass bedding; fotir tubes placed in 

 each of these situations. 



U' Irrigated, cviltivated plots, rice, melons, etc.; pre- 

 viously used melon field now deserted and overgrown by weeds 

 utilized for exjjeriment; five tubes placed in cracks of soil, 

 two tubes under roots of grass. Owing to frequent irrigation, 

 these were the only situations in which ticks covild sturvive. 



- 873 - 



