THE ROTUND TICK. 87 
before becoming engorged to any extent. Guinea pigs and bovines 
were the only hosts upon which nymphs were placed for engorge- 
ment in our experiments. 
TaBLE XXII.—Engorgement of nymphs of Ixodes kingi. 
Nymphs dropped—days fol- 
Num- lowing application. Total 
Datenymphs Fost Num-| ber num- | State of engorge- 
applied. : ber. at- ber ment. 
tached. 5 7 15 16 66 dropped. 
Oct. 25,1909 | Bovine....... 1 Gl Ses oh ees S| ee ee a 1 1 | Two-thirds. 
Nov. 11,1909 |..... cho a rs 5 Nh Cee |e ae 1 | eee 3 y. 
Mar. 29,1910 | Guinea pig... 8 Came sll aoe Sodaane 1 her 1 | Four-fifths. 
Apr. 14,1910 | Bovine....... 1 il I ee lle, ey ol eerie |e a 1] Fully. 
Asprs, 1951910))|.--..-. (Ole) Seose 8 Aha hme’ 1 I a epee [ae eae 2| Three-fourths to 
fully. 
Total. . 23} |e csieinie |e ee re Melee seals oc ce | sac etal eee oe 8 
Of a large number of nymphs applied to hosts only 3 were brought 
to the adult stage. The records on these were made during April, 
May, and June, 1910. The molting periods for these 3 individuals, all 
of which were females, were 29, 33, and 34 days, respectively. An 
average daily mean temperature of 73.29° F. was recorded during the 
minimum molting period and a total effective temperature of 878.4°F. 
was accumulated. 
TABLE XXIII.—Molting of engorged nymphs of Ixodes kingi. 
Engorged nymphs 
molted—days Temperature from dropping 
following drop- Number molted. to date first tick molted. 
Date engorged ping. 
nymphs ap- | Host. Nom 
plied. | : 
Se pee Average 
Fe- Maxi- Mini- . 
29 33 34 | Male. aie. Total. Sarria. Syria. sally 
°F. cls lt 
Apr. 19,1910 | Bovine....| UAE Ree salle | = PARES ALO: 1 1 90. 0 51.50 71.87 
Apr. 26,1910 |...do....-.- 1 OH sciergel| eects 0 1 1 90.0 58.50 73.29 
May 4,1910|...do...... 1 el Se UFO) CEE 1 1 100.0 59. 00 76. 34 
Total. -.| Nl eee. kee arc hae pepe 3 3 
The adult.—One individual of a lot of 3 females which molted 
between May 23 and June 6, 1910, lived about 104 days. One par- 
tially engorged female lived 102 days after being removed from a 
host on September 20, 1909. This tick appeared to be killed by the 
cold. Owing to the fact that very little material was reared to the 
adult stage and both sexes were not obtained at the same time, no 
records of engorgement were obtained. One female put on a guinea 
pig attached in a few hours and died on the host during the second 
day after application. This tick appeared to take some blood prior 
to its death. 
