ANOPLURORUM BRITANNIA. 15 



the body. I remember a case of an old man, whose body 

 I examined after death at the Leeds School of Medicine, 

 which presented one of the most humiliating spectacles it 

 was possible to imagine, from the myriads of this species 

 which were crawling over every part of it. In the nostrils, 

 eyes, and corners of the mouth, were numbers congregated, 

 and although the greater part of his hair had been cut off, 

 what remained was literally swarming. This subject had 

 died in one of the Fever Hospitals, and I considered the case 

 rather uncommon, inasmuch as the Head Louse is not like 

 its congeners, the companion of disease, or at least, ill 

 health, produced from some temporary accident. On the 

 contrary the Capitis, it is well known,' is common upon the 

 most healthy children, as well as upon adults at particular 

 periods, whose habits are not in the least uncleanly. 

 Latreille states,* that the Louse found on the head of the 

 negro is black, while that of civilized Europe is whitish. 

 The former, I believe, he considers as a species, and de- 

 signates it nigritarum ; Stark queries its being anything 

 more than a variety of the humanus. If it is a variety at 

 all, which I do not see any reason for supposing, it would 

 more probably be of the Capitis. Blumenbach states that 

 from his own knowledge the human Pediculus is also found 

 on the Simia Troglodytes, and on the Cercopithecus 

 paniscus. I do not presume to dispute such high authority, 

 but would venture to observe, that the species of this 

 family approach in many cases so closely, that any person 

 who had not examined very minutely, would fail to detect 

 the diagnostic marks, by which alone two similar species 

 may be distinguished. I have found a Pediculus upon the 

 Green monkey certainly very like the human species, 

 but much smaller, and Dr. Burmeister enumerates one 



* Nouv. Die. et Hist. Nat. vol. xv. p. 152. 



