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OBSERVATIONS ON THE BIOLOGY OF THE 
IXODIDAE. 
PART III. DEALING WITH THE BEHAVIOUR OF THE SEXES IN 
AMBLYOMMA HEBRAEUM, HYALOMMA AEGYPTIUM AND RHIPI- 
CEPHALUS BURSA* WHEN UPON THE HOST. 
By GEORGE H. F. NUTTALL, F.R.S. 
The experiments herein recorded were conducted with a view to supplementing 
the biological studies on ticks previously published by me in Parasitology, 
Vols. vi and vii, and, more particularly, to acquire a knowledge of the 
behaviour of the sexes upon the host. For this purpose, ticks belonging to 
three different genera were employed, i.e. Amblyomma, Hyalomma and 
Rhipicephalus, since their behaviour was likely to differ more widely than in 
members of one genus, although some members of the recognised genera, as 
I am perfectly aware, may differ still more widely in their habits than do 
the species to which this communication relates. 
METHODS. 
The adult ticks were placed upon a ram’s scrotum enclosed in a canvas 
bag of suitable size which could be tightened at the neck by drawstrings 
running in opposite directions through a seam at the top of the bag. 
Furthermore the latter was secured by two cords that ran belt-wise around 
the animal. That the behaviour of the ticks in this confined area is practi¬ 
cally the same as when they are permitted to roam at will upon the host was 
amply proved in my earlier experiments. 
The ticks were given identification marks by painting a part of their 
backs with various colours. The paints, consisting of different kinds of 
sealing wax dissolved in alcohol, were applied to the ticks by means of a 
sharply pointed match. The alcohol evaporated soon after the paint was 
applied, and the hard glossy crust of wax that was formed in no way affected 
the ticks adversely. The colours had to be reapplied from time to time and 
no confusion of individuals resulted by the use of the method, except in 
some cases with R. bursa males, to whose smooth glossy backs the wax 
adhered badly. 
Coloured lines were drawn with greased pencil upon the surface of the 
scrotum, front and back, whereby it was divided into areas which facilitated 
