LIFE HISTORY OF CATTLE TIOK. 29 
‘same time. In the case of males, while during and after the first molt 
the tick remains fixed to the host, after the second molt it detaches 
itself and travels in search of a female. As a rule the males molt two 
or three days ahead of females and frequently two are found attached 
to the skin of the host directly beneath nymphal females, awaiting 
the molting of the latter. 
When the adult stage is reached the development is very rapid. 
In from as few as 4 to 14 days the females become fully engorged 
and fall to the ground to deposit their eggs. They die when the 
operation is completed. 
Although female ticks are somewhat more easily removed at the 
time of molting than at other times, repeated careful observations 
show that they do not actually detach themselves at either molt. 
However, Mr. B. H. Ransom has shown that, when detached arti- 
ficially just before or after the second molt, females will reattach if 
placed upon another animal.“ Likewise he found that ticks removed 
just after the first molt would reattach after 24 hours. Specimens 
detached just before the second moit transformed and lived without 
host for two weeks. Several experiments have led us to the con- 
clusion that only in the rarest accidental cases can reattachment 
normally take place. In many cases we have attempted to cause 
detached ticks to reattach, but in only two cases did we succeed. 
The following are some of the particulars: 
February 23, 1906, eight ticks, ranging in size from nymphs to one- 
half engorged adults, were placed on the shoulder of a steer. The 
next day all but one of these ticks had disappeared. One, however, 
which was about one-half engorged, had fastened to the skin about 
6 inches from the point where it was placed. This tick was found 
detached on March 1 and trying to crawl out from the hairs which 
had been glued together to hold it in place. At this time it was not 
fully engorged. It began depositing eggs on March 18, and con- 
tinued oviposition until April 26, reaching a total of 523 eggs. An 
attempt was made to cause these eggs to hatch, but without success. 
It is not likely, however, that the failure to hatch was due to the 
experience of the tick. It is probable that the state of engorgement 
may have had something to do with the matter, and, moreover, at 
the time of the year when the eggs were under observation it is 
exceedingly difficult to cause them to hatch. After the experiment 
that has been mentioned repeated attempts were made to obtain 
other cases of reattachment. Ticks at various stages were placed on 
a ahille (Contr. l Etude Ixodidés Argentine, p. 112) had previously detailed a num- 
ber of experiments in the reattachment of Margaropus (Boophilus) microplus. Tt was 
found that immediately after molting the ticks would more or less frequently reattach 
after being removed artificially. Nothing, however, was found to indicate that the 
parasites naturally detach and reattach on the host, 
