ENTOMOLOGY 995 
Pediculus (Pediculus) humanus humanus Ewing, 1926, Proc. U. 8. Nat. Mus., LXVIII, Art. 19, 
p. 22, figs. 14, 2, 3A and 7; Pl. II, fig. 8( 9). 
Liseria. — Moylakwelli, October 28, 1926, off native Liberians of the 
Kpwesi tribe. 
BELGIAN Conco. — Lulenga, March 3, 1927, head lice off natives (Wanya- 
ruanda; native name, ‘“‘inda,’’ used for both body and head lice). 
Pediculus humanus corporis de Geer 
Pediculus humanus corporis de Geer, 1778, ‘Mém. pour Servir 4 |’ Histoire des Insectes,’ VII, p. 67, 
Pl. I, fig. 7 (Europe). 
Pediculus vestimentt Nitzsch, 1818, Germar’s Mag. Entomol., III, p. 305 (without description). 
Pediculus (Pediculus) humanus corporis Ewing, 1926, Proc. U.S. Nat. Mus., LX VIII, Art. 19, p. 18. 
LIBERIA. — Gbanga, September 13, 1926, body lice off native Liberians of 
the Kpwesi tribe. Moylakwelli, October 28, 1926, body lice off native Libe- 
rians of the Kpwesi tribe. 
BELGIan Coneo. — Lulenga, March 3, 1927, off natives (Wanyaruanda). 
It is interesting to note that both head and body lice were found on the 
natives of the hinterland of Liberia, who have come but little in contact with 
Caucasians, perhaps less so than any other African tribes. 
Two diametrically opposed views have been held with regard to the identity 
of the body and head lice of man. According to Nuttall,’ typical capitis and 
corporis are the extremes in the variation of the one species, Pediculus hu- 
manus, and they are identical in all essential points of structure; they merely 
represent two unstable races of one species, to be distinguished partly from 
practical considerations.?, Not only do they interbreed as was shown by Bacot 
and Sikora; but, what is more important, Keilin and Nuttall claim that a 
strain of typical capitis may be transformed experimentally after a few gener- 
ations into typical corporis.’ If this were actually the case, head and body lice 
would be no more than adaptive forms, such as are exhibited by the so-called 
amphibious plants (Polygonum amphibium, for instance). 
The opposite view that body and head lice are genetically quite distinct, 
either as species or as subspecies, has also had many advocates, and at various 
times entomologists have believed that different races of mankind each har- 
1 Nuttall, G. H. F. 1919. ‘The systematic position, synonymy and iconography of Pediculus 
humanus and Phthirus pubis.’ Parasitology, XI, pp. 329-346. 
1920. ‘On Fahrenholz’s purported new species, subspecies and varieties of Pediculus.’ Parasitology, 
XX, pp. 136-153. 
2 From Nuttall’s remark in a footnote to his 1919 paper (p. 345), that ‘“‘the two forms are insuffi- 
ciently fixed to be regarded as varieties,” it would seem that he uses the term ‘‘race’’ not to cover the 
usual concept of a geographical or biological race, or subspecies, but rather that of a “form” wholly due 
to environmental conditions and not hereditary. 
3 Bacot, A. 1917. ‘A contribution to the bionomics of Pediculus humanus (vestimenti) and Pediculus 
capitis.’ Parasitology, IX, pp. 228-258. 
Keilin, D. and Nuttall, G. H. F. 1919. ‘Hermaphroditism and other abnormalities in Pediculus 
humanus. Parasitology, XI, pp. 278-328, Pls. XII-XVII. 
H. Sikora also was at first inclined to believe that head lice when bred on the body could be changed 
into body lice (1917, Arch. f. Schiffs- u. Tropenhyg., XXI, pp. 275-284). She found, however, that this 
did not even happen after eleven generations (1919, Arch. f. Schiffs. u. Tropenhyg., XXIII, pp. 65-67) 
and she now believes that the many intermediate specimens are due to crossing. 
