.82 Gerald F. Hill : 



that the young " ticks " first mated on the eleventh day, extruded 

 the first pupae about the twenty-first day, their second pupae about 

 the thirty-first day, and their third pupae about the thirty-ninth 

 day. 



Exptrimtni xVo. 5. 



An experiment similar to the above in all particulars excepting 

 in the number of "ticks" used Avas commenced, on January 23rd, 

 with twenty-five " ticks," about twelve hours old. The fleece was 

 searched daily, and many dead " ticks " were removed, especially 

 during tlie first few days. On tlie fourteenth day (February 6th) 

 one pair was found copulating. On the twentieth day (February 

 12th) the fleece was caiefully searched for ** ticks " and their 

 pupae, with the result that only five " ticks " could be found. On 

 the twenty-third day (February 15th) two pupae were found. On 

 the thirty-second day (February 24:th) the fleece was very carefully 

 searched to ascertain the number of surviving ** ticks," which was 

 three males and two females. Two pupae were found also. 



Thus assuming tliat copulation did not take place earlier than 

 February 6th, and that the four pupae were all extruded by the two 

 females found on February 24th, it will be seen that the first mated 

 when about fourteen days old, extruded the first pupae about the 

 twenty-third day, and the second pupa about the thirty-second 

 day. 



Many other experiments similar to, or modifications of. Experi- 

 ment No. 3, page ^^0, were undertaken, but in none of them was I 

 able to obtain any useful data. It was found impossible to firmly 

 secure a buckram or muslin enclosure to the host for more than a 

 day at the longest. In one experiment only (No. 3, p. 80) could 

 the " ticks " be kept alive and under observation for a sufficiently 

 long period to enable me to obtain the desired information, and 

 after repeated failures this method was aljandoned. Collars made 

 of tin or modelling wax were tlien tried. With the aid of melted 

 pitch plaster it was found possible to secure these enclosures in 

 position for several days, and, fui'ther, as the ** ticks " were unable 

 to crawl up the smooth inner surface, it -was not necessary to cover 

 the top of the enclosure. The young " ticks," however, soon died 

 in these enclosures, and in no case did one live to i-eacli maturity. 

 The writer's experience with " ticks " confined in small enclosures 

 on the host agree with Swingle's, i.e., such "ticks" will not live 

 for more than a couple of weeks, very rarely so long. 



