G. H. F. Nutt ALL 
179 
size backward, absent on coxa IV which is rounded; coxa I visible 
dorsally owing to its protruding anterior angle; trochanters unarmed^’, 
movable articles slender ; tarsus 4 tapering obliquely, claws much longer 
than the pad. 
II. Types of parasitism in ticks illustrated. 
Having frequently had occasion to explain to students the different 
types of parasitism observed in ticks, it occurred to me recently that 
these types could, with advantage, be illustrated graphically for the 
purpose of instruction. 
The life-cycles of the ticks are represented in the accompanying 
diagram. Fig. 2, in the form of a dial, the various stages being named at 
the periphery; lines running to the centre enclose corresponding areas 
ATTACK HOST 6 
TO 7 A ia H A Jr;; T FUMF. 
07n*0SlT3 THIRD OR 
FOERTH TIUH. 
ADUUTS ATTACK HOST S 
A ND HAIE; TS2161S. 
OVn^SETS SECOND TBE^ 
ATOUTS ATTACK HOST 4-. 
AND HATE; FEiALS 
oTiPosirs rnisT the. 
1 ESPICTE FECU-HATED TELIAl^ 
' DROPS TBm HOST. 
UALSJilSZS.iSI. 
,07IP0Sin0N COiaE-’CES. 
LARVAE HATCH OOT. 
•LARVAE ATTACK HOST I. 
FIRST KYHPHAL STAGS 
EUESGES raOM LARVAl 
SKni 
u s Aj r a jxtua nuax. 
ADOLTS ATTACK HOSTS 
6, 7, 8, OB LURE.. * 
ADULTS APPEAR ETC^ 
first N!a£PH ATTACKS 
HOST 3 a;JD DROPS 
OTF REPLEIE 
SECOND NXMPHAL STAGES 
SECOND IJY!£PH ATTACJS 
HOST 3 A:D drops OFF 
EULEEE 
ADULTS ATTACK HOST 3 . 
a:D HA 3 E. 
MALE irvza HU. 
^ovn^smo:! commeijoes. 
. _ LARVAE HATCH OUT BUT 
N/v STL AI El E POS - 
THT-T V DCLIIOT J!ESD. 
ESPIETE FECD:iIlATED FEMALE 
DROPS TROM HOST 3 
■E’osmo:! COUIEICES 
DTTR 
LARVAE HATCH OUT 
ADULTS EtEtCE FROy 
»raiKlAL SKEl 
van^sT ai ®od:d 
PEPLETE FECH,'DATED FEIALE 
DROPS FROD HOST 2 
MALE .PISS 
oviPosin<ai coime.’ces 
FEMALE DUS . 
LARVAE HATCH OUT 
LARVAE ATTACK ECXST 1 
-1TY1IFH3 EtlTifE FRC2i 
LARVAL 31031 VEILST 
■ ON GROUID 
! inairas ATTACK host s 
EEHETE irC-IHS lEQ? 
FROM HOST 2 
adults attack host 2 . 
AID WATP 
ADULTS TVER gE FRO M 
TTr^rPK AT, , STO:! KHnDT 
q:{ ®ou:d. 
Pr\>AT.r T.T7F3 ( 
FIRST KILffHAL STAIE 
Fi.ffTRgffH raoM I.ARVAL 
SKDl. 
^ FIRST KSMPH ATTACKS 
' HOST I a:d drops off 
N beucte. 
^ ' SEOCCD WIMEHAL STAfE 
\ Timyff’a , 
' HEOOID II2JPH ATTACKS 
HOST 2 AID DROPS OFF 
_ REPLETE. 
THIRD NTMFHAL STAGE 
EMERGES. 
THTOD inCMEH ATTACKS 
HOST 4 ETC. 
RSIETE FECU! DATED FT2£Al£ 
, DROPS FROM HOST I 
.CVIPOSiriOlt COMMEICES 
i^RVA^ HATCH OUT 
KSIPSS DROP 
TSJSL HOST I. 
• LARVAE ATTACK HOST 1 
HmiETE LARVAE RP’.«ait . 
OR HOST I 
FROM 
• LARVAL SKEI WHILST 
OH HOST I 
IDCifroS FSATTACH TE^fSELVES 
TO BOOT X» 
ADULTSEEATTACH 
THFMSEIi'VES TC 
HOST I AID MATE, 
ADULTS E2iE34GE FROM' 
tnCiPHAL SKIN WjTTTJT? 
ON ffilST I. 
LAK7AE ATTACK HOOT 1. 
FSPLSTZ LARVAE 
OH HOST I, 
•JQMFHS SLERiE FROM 
LARVAL SICCI TEELST 
' a:r host. 
, tmrss KEATZaCB THEMHELVES 
_’ TO HOST I, 
EEETJUE KiOiFES REMAIN 
ON HOST I* 
Fig. 2. Diagrams representing graphically the different types of parasitism 
observed in ticks (refer to text). 
1 Differing in this respect from the female, nymph and larva. 
