88 DIRECT INJURIES CAUSED BY INSECTS. 



Dr. Willan, in one case of Prurigo senilis, observed 

 a number of small insects on the patient's skin and linen. 

 They were quick in their motion, and so minute that 

 it required some attention to discover them. He took 

 them at first for small Pediculi ; but under a lens they 

 appeared to him rather to be a nondescript species of 

 Pulex^; yet the figure he gives has not the slightest 

 likeness to tlie latter genus, while it bears a striking 

 resemblance to the former. It is not clear Avhether his 

 draughtsman meant to represent the insect with six or 

 with eight legs : if it had only six, it was probably a 

 Pediculus ; but if it had eight, it would form a new 

 genus between the Acaridce and the hexapod Jptera. 

 Dr. Bateman, in reply to some queries put to him, at 

 my request, by our common and lamented friend Dr. 

 Reeve, relates that he understood from Dr. Willan, in 

 conversation, that the insect in question jumped in its 

 motion. This circumstance he regards as conclusive 

 against its being a Pediculus ; but such a consequence 

 does not necessarily follow, since it not seldom happens 

 that insects of the same genus either have or Jiave not 

 this faculty ; for instance, Ci/pJion hemisphcericKs, Aca^ 

 rus Scabiei, &c. 



Dr. Willan has quoted with approbation two cases 

 from Amatus Lusitanus, which he seems to think cor- 

 rectly described as Phthiriasis, In one of them, how- 

 ever, Avhich terminated fatally, the circumstances seem 

 rather hyperbolically stated — I mean, where it is said 

 that two black servants had no other employment than 

 carrying baskets full of these insects to the sea ! ! Per- 

 haps you will think I draw largely upon your credulity 

 if I call upon you to believe this ; I shall therefore leave 



* On Cutaneous Diseases, 87, 88 ; and 1. 1. /. 4. 



