Gr. H. F. Nuttall 
143 
Fahrenholz (1919, p. 27) renamed the form assimilis finding the name 
oblongus preoccupied. This form was regarded by me (x. 1919, pp. 337, 340) 
as probably P. humanus race capitis, and I am confirmed in this belief by the 
foregoing diagnosis which has since become accessible. 
II. 
EVIDENCE DISPROVING THE VALUE OF THE CHARACTERS WHEREBY 
FAHRENHOLZ DISTINGUISHES THE BEFORE-MENTIONED FORMS OF 
PEDICULUS. 
Of the older authors who have examined lice obtained from different races 
of man, Murray (1861), whom I have cited elsewhere (ii. 1919, p. 206), did 
not venture to regard such lice as belonging to distinct species. He does not, 
however, distinguish clearly between head-lice and body-lice in reaching his 
conclusions. Piaget (1880, p. 623), who regarded corporis and capitis as 
separate species, in referring to the latter, fully appreciated its variability, 
for he wrote: 
“11 ne me semble pas qu’il faille attacher beaucoup d’importance a ces 
differences. En examinant un plus grand nombre d’individus de la meme 
race, il en sera probablement comme de ce que j’ai eu sous les yeux. Quelques 
individus avaient le cote interne de la griffe dentelle, d’autres entierement 
lisse; la couleur passait du gris au jaunatre. C’etait le cas chez les parasites 
d’Europeens et de Malais faisant partie de ma collection. Du reste, je ne vois 
pas que Ton puisse tirer de ces minimes differences quelque argument pour 
ou contre l’unite d’origine des races ou especes humaines.” 
Neumann (1910, p. 411), who also quotes the foregoing passage from Piaget, 
lays stress on the need of examining many adult lice from various races of 
man before reaching conclusions. Having examined many such specimens, 
he concluded that “les transitions sont insensibles entre la forme type (euro- 
peene) et les diverses formes exotiques et que Ton est porte a les reunir toutes 
en une espece unique.” The pigmented chitinous structures which possess 
great taxonomic value in Anoplura, correspond in lice from negroes “a des 
renforcements chitineux, incolores ou peu colores chez le pou de l’Europeen. 
II en resulte que P. capitis est infiniment mieux caracterise par les specimens 
des races noires....” 
It is remarkable that Eahrenholz should attach importance to the super¬ 
ficial statements of the earlier authors I have cited on p. 137 and not have 
taken a warning from the writings of vastly more careful observers like Murray, 
but especially Piaget and Neumann, whom I have just quoted. 
The subject of the relation between capitis and corporis has already been 
discussed at length by me ( Parasitology , xi. pp. 339 et seq.) and I see no reason 
to modify my statements in view of those of Fahrenholz’s publications which 
have since become accessible to me in the original. I was thinking not only 
of Fahrenholz but also of others when I stated (Ibid. p. 333) that “Such 
Parasitology xii 
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