G. H. F. Nuttall and C. Strickland 
303 
the tick had derived its food before it attacked the collector. The tick 
was removed almost immediately after it attached itself and it is doubt¬ 
ful if it actually drew any blood before it was forcibly detached. The bite 
produced a large violet ecchymosis within a few minutes and it took 
months for the wound to heal. On arrival in Cambridge this tick was 
allowed to bite a fowl with the result that a large haemorrhagic spot 
appeared about the wound, whilst the tick was feeding, and within half- 
an-hour or so an irregularly circular ecchymosis had formed measuring 
about two inches across. After the meal of fowl’s blood had been 
digested it was again fed on a fowl on two occasions, but in neither 
case did any reaction take place around the seat of the puncture. 
When fowls or other animals have been bitten by A. persicus or 
0. moubata in Cambridge, in the great majority of cases no reactions 
occurred about the minute punctures, but occasionally small ecchymotic 
areas appeared pointing, as in the case of 0. coriaceus above cited, to 
a direct toxic action. 
It is not known if ticks do or do not regurgitate material from their 
digestive tract whilst feeding. Should it be proved that regurgitation 
occurs, then an explanation of the occasional toxic effects might be 
found in the character of the regurgitated material which has been 
derived from a previous meal. On the other hand our experiments 
show that there may be considerable differences in the amount of 
anticoagulin which is present in the salivary glands of individual ticks. 
We may conclude from this that the amount of effective secretion 
injected into the wound may vary. But leaving hypothesis aside, it 
appeared desirable to learn something by experimental methods 
regarding the possible character of the salivary gland secretion. 
A careful search of the literature has only brought to light one 
paper bearing upon the subject from the experimental standpoint. The 
investigations of Sabbatani (1898—1899), at Cagliari, demonstrated 
that the bodies of Ixodes ricinus and $ ) contain a substance which 
retards or prevents coagulation,—an anticoagulin. We have been able 
to go a step further by demonstrating the presence of anticoagulin in 
the salivary glands and intestines of A. persicus. 
Sabbatani carried out his experiments as follows : 
He removed replete female ticks from dogs, cut them in pieces with 
scissors, rubbed them up in a mortar together with salt solution, and 
filtered the fluid through muslin. Having added a known quantity 
of salt solution to a definite weight of ticks he utilized quantities of 
“ tick solution ” which corresponded to a given number of ticks 
