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SOME OBSERVATIONS ON THE BIOLOGY AND 
STRUCTURE OF ORNITHODORUS SA VIGNY I, 
ANDOUIN. 
By NORMAN CUNLIFFE, M.A. (Cantab.). 
Christopher Welch Lecturer in Economic Zoology, University of Oxford, and 
formerly Student in Medical Entomology, Quick Laboratory, Cambridge. 
(With 3 Text-figures.) 
CONTENTS. 
Introduction. 
Section I. Biology of O. savignyi ........ 
Experimental records relating to females kept at different temperatures 
Oviposition ........... 
No evidence of parthenogenesis ....... 
Longevity of female tick ........ 
Duration and number of nymphal stages at 30° and 37 C. 
(а) Experimental data ........ 
(б) Discussion of data ........ 
Duration and extent of engorgement ...... 
The influence of moisture on vitality and ecdysis .... 
Section II. Structure of 0. savignyi •.....• 
Dimensions of egg ....•••••• 
Dimensions of unfed stages . . . ... 
Changes in external anatomy undergone during development (a) hypo 
stome, ( b ) leg and spiracle ....••••• 
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INTRODUCTION. 
Some observations on the biology and structure of Ornithodorus moubata have 
been recorded in a recent communication to this journal (Cunlifie, 1921) and 
in the following pages all references to this species refer to these observations, 
unless otherwise stated. Prof. Nuttall received living material of 0. savignyi 
from Dr J. H. Ashworth in 1911 (from Aden, Quick Lab. Cat. No. 1575) and 
again in 1913 (no data, Cat. No. 2011). These stocks being available for 
breeding experiments, a few observations on the biology and structure of this 
species were made in the years 1913-14. 
Even at the present time, details of the life-cycle of O. savignyi appear to 
be unknown. Howlett (1916) and Fletcher (1919) have both stated that this 
Parasitology xiv - 
