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THE BIOLOGY OF PEDICULUS HUMANUS. 
By GEORGE H. F. NUTTALL, F.R.S. 
(From the Quick Laboratory, University of Cambridge.) 
(With Plates II and III and 12 Text-figures.) 
CONTENTS. 
Introduction ..... 
PAGE 
82 
Part I. 
PREVALENCE AND MODES OF DISSEMINATION. 
Prevalence of lice among the poorer classes .... 83 
Relative frequency of infestation with different lice . . 84 
Greater prevalence of capitis in children and old people . 84 
Number of pediculi that may infest a person ... 86 
Seasonal variation in the number of lice on man . . 87 
Influence of climate on lice ...... 90 
Distribution of corporis on man’s clothing and person ... 91 
Distribution of capitis upon man’s body .... 94 
Modes of infestation and dissemination of Pediculus . . 94 
Locomotory powers of lice on cloth and hair . . 99 
Dissemination of lice by the wind ..... 103 
Dissemination of lice by house-flies .... 104 
Part II. 
METHODS. 
Methods of raising lice experimentally ..... 104 
Attempts to raise lice by feeding them on animals, with notes 
on their occasional occurrence on different animals. 112 
Collecting, forwarding and preserving lice . . . . 113 
Part III. 
SPECIAL BIOLOGY. 
The relative proportion of the sexes on the host . . 114 
Disparity in the proportion of the sexes in different broods. 115 
