386 REPORT—1905. 
nymph the ‘larva-nymph stage,’ and that from the dropping of the 
nymph to the appearance of the adult, the ‘nymph-adult stage.’ In the 
laboratory the adult-larva stage has ranged from forty-three to ninety- 
three days (six observations) in summer, and from 222 to 309 days 
(seven observations) when winter was included. The larva takes 
2% days or longer to feed, the nymph generally four, and the adult 
female five or six when the two sexes are applied together. Our 
shortest larva-nymph stage record is twenty-seven days, January 26 to 
February 22, and our shortest nymph-adult fifty-two days, March 12 to 
May 3. These records were made at ordinary temperature between the 
dates given. Under out-of-door conditions the life-cycle must generally 
extend over a full year. The sexes attach independently, and after about 
three days the male releases his hold and seeks a mate. It is very 
common to find the male adhering to his mate when she is one third or 
more developed, with his rostrum buried in the genital pore ; and he may 
remain thus affixed for days, even should the female become fully 
engorged and be removed. If forcibly detached, he generally loses no 
time in regaining the position. The male of the English Jiodes ricinus 
behaves similarly ; and the object is conjectured to be coition. It is very 
unusual to find any of the other South African ticks thus sexually 
united, but by the examination of many hundreds of pairs the observation 
has been made once or more on Argas persicus, Onithodoros savignyt var. 
cecus, Amblyomma hebreum, Rhipicephalus evertsi, and Boophilus 
decoloratus. 
No species of Apononma has been reared by us. Two species, A. leve 
var. capensis and A. exornatum, have been collected, the former in the 
adult stage from a black snake and the latter in the nymph and adult 
stages from the iguana (Varanus sp.). 
The genus Amb/yomma contains three South African species that have 
come to our notice. The bont tick, A. hebreum, has been given the 
closest attention. This species appears to be able to subsist on any warm- 
blooded animal. We have fed it, or found it attached in all its stages, on 
the horse, ass, ox, sheep, goat, dog, ostrich, fowl, antelopes of several 
species, and man. The ox, however, is its principal host, and the one to 
which it is best adapted. As larva and nymph it freely attaches to any 
part of the body ; but as the adult it does not commonly attach high on 
the flanks, along the back, or about the head. Eggs laid in the spring 
and early summer generally hatch before cold weather, but those laid in 
late summer and during the winter usually remain unhatched until mid- 
summer of the following year. The shortest adult-larva.stage at ordinary 
temperatures that we have observed took seventy-six days, and the longest 
279 days. The time required for the larva to become distended on the 
host varies slightly with the kind of animal, and more with the part of 
the animal, to which the tick is attached, presumably owing to the greater 
ease with which the blood is drawn at one place than another. The stay 
is usually about six days, but may be as short as four or as long as twenty. 
The larva-lymph period in an incubator kept constantly between 90° and 
100° F. occupies fifteen days; at ordinary temperatures it has occupied 
from 23 to 120 days. The nymph commonly takes a little longer to feed 
than does the larva, but many specimens have taken only four and a 
quarter days ; a few have taken twenty-five to thirty. The nymph adult 
period is about eighteen days in the incubator ; at ordinary temperatures 
it has ranged from 27 to 160 days. The male takes up a position on an 
