•293 
STUDIES ON PEDICULUS. 
I. THE COPTJLATORY APPARATUS AND THE PROCESS 
OF COPULATION IN PEDICULUS HUMANUS. 
By GEORGE H. F. NUTTALL, F.R.S. 
{From the Quick Laboratory, University of Cambridge.) 
(With Plates III and IV and 12 Text-figures.) 
CONTENTS. 
P.40E 
Introduction .......... 203 
Certain essential differences in the anatomy of the sexes . 294 
Historical: Regarding the Copulatory Apparatus of the Male 
and Female.296 
The Author’s description of the Copulatory Apparatus: 
The male apparatus ....... 301 
General description of the extruded apparatus 
(chitinous structures) ...... 301 
Component parts of the apparatus .... 304 
Mechanism ......... 309 
The female apparatus . . . . . . . 312 
The act of copulation: 
Historical .......... 316 
The Author’s observations ...... 317 
Note on the nomenclature of parts ..... 322 
Key to the lettering accompanying the illustrations . . 323 
Explanation of Plates ........ 324 
References .......... 324 
Introduction^. 
Owing to the active interest now being taken in all that concerns 
lice and their habits, especially in connection with the war, it seems 
expedient to forestall a fuller publication, now in preparation, by 
* I am much indebted to Dr D. Keilin for his very able and friendly assistance in 
connection with the work upon which this paper is based. 
