80 LIFE HISTORY OF NORTH AMERICAN TICKS. 
the genital orifice of the female but that he does not know the sig- 
nificance of this action. We have observed copulation in Argas min- 
vatus in a number of instances. The act has been witnessed most 
frequently a few hours after engorgement. The male crawls beneath 
the female and inserts the hypostome into the female genital orifice. 
In about five minutes the mouth parts are withdrawn and the male 
moves slightly forward and deposits a large spermatophore, the end 
of which is inserted in the female aperture. The contents of the 
spermatophore appear to be pressed out by the body of the male. 
The empty spermatophore is usually left attached to the posterior 
margin of the genital opening of the female. This collapsed sack was 
found to measure about 0.387 mm. long (parallel with the axis of 
the tick) by 0.502 mm. broad. Nuttall and Merriman (1911) have 
made very careful observations on the copulation of Ornithodoros 
moubata; the process is very similar to that which occurs in Argas 
miniatus. 
With the Ixodide copulation usually takes place on the host, 
although males of a number of species have been observed with the 
mouth parts inserted in the genital openings of females while off the 
host. This habit was first observed by De Geer (1778). Among the 
ixodid ticks it appears to be the most common in species of the 
genus Ixodes, having been observed by Wheler (1906, p. 425) in J. 
ricinus and I. hexagonus and by the writers in J. scapularis and 
I. californicus. Samson (1909), who has made observations on this 
act in Ixodes ricinus, states that no spermatozoa were found in the 
female genital pore when a male which had its mouthparts inserted was 
removed. However, males were observed to withdraw the mouthparts 
and to bring the genital pore into contact with that of the female, then 
reinsert the beak as though pushing the spermatophore into the 
female orifice. This habit of the male in introducing the hypostome 
into the vulva, so commonly observed among species of the genus 
Ixodes, has been less frequently observed in other ticks. Wheler 
(1906, p. 425) has also observed the habit in Ceratizodes putus. 
Dénitz (1905, p. 125) reports its occurrence in Rhipicephalus appen- 
diculatus and R. evertsi as well as in J. ricinus, and Lounsbury 
(1905) has observed it one or more times in Amblyomma hebreum, 
Rh. evertsi, Margaropus decoloratus, Argas persicus, and Ornithodoros 
savignyi ceca, as well as in J. pilosus (1900c). 
With the species which molt upon the host, the male usually 
reattaches very shortly after the nymphal skin is shed and, follow- 
ing a short period of feeding, goes in search of the female. In most 
of the species which drop to molt it seems to be necessary that the 
male attach and engorge blood before the sexual instinct becomes 
manifest. The period required for fecundation appears to vary 
considerably. Some species, namely, Margaropus annulatus, Der- 
