378 
Pathological effects of Phtliiriis 
them as the cause, and Ids pupil Moursou (1877-78)^ published the 
results of many clinical observations which showed that the spots were 
invariably associated with the presence of crab-lice, although the latter 
might be present without the maculae^. Moursou found no spots in 
the early stages of infestation, they only appeared 12-21 days later, 
i.e. when the lice had reached the adult stage (compare with my experi¬ 
mental observations described on p. 380 infra). 
Duguet (1880-1-2) first demonstrated experimentally that the spots 
are due to Phthirus, by puncturing the skin with a lancet charged with 
the substance of the crushed lice, typical spots appearing at the points 
of inoculation after an interval of 12 hours. He uext cut the lice in 
pieces and inoculated men with the substance obtained from the head, 
the forepart, middle, and hind part of the louse’s body. The only part 
of the insect which produced the spots when inoculated was the thoracic 
region, corresponding to the portion whence spring the second pair of 
legs, i.e. the region which includes the louse’s salivary glands. If these 
glands were torn out with the head, then the crushed head produced 
a spot when inoculated. When Duguet inoculated the substance of 
crushed nits, the result was negative. 
Ciuffu (1907, p. 260, cited by Tieche) also produced the spots by 
subcutaneous inoculation, but was unable to do so by scarifying the skin. 
Cause of the coloration. Oppenheim (1901«, p. 451)^ states that 
Phthirus, by means of a ferment (oxydase) that is present in its salivary 
glands, is capable of forming a pigment, similar to biliverdin, which is 
derived from human blood and is deposited in the insect’s fat body. 
According to Oppenheim, this pigment is likewise formed in the human 
body when the louse bites, the pigment giving rise to the maculae. 
Oppenheim mentions that the pigment was observed by Ehrmann to 
occur in the cells of the insect’s fat-body at the sides of the thorax and 
abdomen, and that it is not identical with biliverdin. In following the 
development of Phthirus, I observed that the green coloration of the 
louse’s body in the regions indicated, appeared as the insect attained 
sexual maturity, being most marked in the oldest adults. The signifi¬ 
cance of this pigment remains to be determined. Oppenheim’s statement 
that the pigment is formed by a ferment in the salivary glands, (a) in 
the louse’s body, and (h) beneath human skin, appears to me to be an 
For references see Bibliography, p. 27. 
^ Braulfc and Montpelher (1914, p. 78) record a case of general infestation in an Arab 
on whose dark skin no spots were visible. 
® I cite from the authoi-’s abstract, the full paper being inaccessible. 
