°0 LIFE HISTORY OF NORTH AMERICAN TICKS. 
HISTORY OF THE BIOLOGICAL STUDY OF TICKS. 
The first studies made of the life history and habits of ticks were 
those of Dr. Cooper Curtice (1891, 1892a, b) on the cattle tick 
(Margaropus annulatus) conducted in cooperation with the Texas 
Agricultural Experiment Station at about the time that Drs. Smith 
and Kilborne were investigating the réle of that species in the trans- 
mission of splenetic fever. From the time of these investigations by 
Dr. Curtice up to 1898 little attention seems to have been given 
to the biology of ticks other than this species, although a prelimi- 
nary study was made of Amblyomma variegatum (Hyalomma venustum) 
in Antigua, by C. A. Barber (1894-95). 
In 1898 Dixon and Spreull reported studies made of Margaropus 
decoloratus and the same year Prof. C. P. Lounsbury, the entomologist 
of Cape Colony, British South Africa, began his classic studies of the 
Ixodoidea. Since that time Lounsbury has worked out the life 
history and habits of a large number of South African species. 
During the course of these studies he has demonstrated the trans- 
mission by ticks of three distinct diseases of domestic animals and 
the pathogenicity of at least seven species of ticks and has determined 
the stages of imbibition and of inoculation of the hosts with the 
disease-producing organisms. 
In 1898 Dalrymple, Morgan, and Dodson, of the Louisiana Agricul- 
tural Experiment Station, published a detailed account of experi- 
ments relating to the life history of the cattle tick. The information 
which they furnished upon the longevity of the ‘‘seed ticks” served 
as a basis for the feed-lot and pasture-rotation system for cleaning 
stock and pastures of the cattle tick. In 1899 Prof. H. A. Morgan 
published further information upon the life history of the cattle tick 
and included data upon the biology of Amblyomma americanum, 
Dermacentor variabilis (electus), and Ixodes scapularis (not ricinus). 
In 1899 E. G. Wheler, in England, published an account in which : 
he reported studies made of Ixodes ricinus and the same year C. J. 
Pound published notes on the Australian cattle tick (Margaropus 
annulatus australis). In. 1903, Dr. H. Kossel and his coworkers pub- 
lished an account of studies of the biology of Jxodes ricinus in a report 
of investigations made in Germany in which they found it to transmit 
bovine piroplasmosis. During the course of his investigations of the 
various protozoan diseases of animals in South Africa, Dr. Arnold 
Theiler, veterinary bacteriologist to the Transvaal, has added much 
to our general knowledge of the biology of ticks. Dr. H. T. Ricketts, 
in connection with his investigation of Rocky Mountain spotted 
fever, has published information from time to time (1907, 1909a, b) 
upon the life history and habits of Dermacentor venustus. Prof. R.A. 
Cooley (1908, 1911) and W. D. Hunter and F. C. Bishopp (1911a, b) 
