214 Prof. J. C. Schjddte on Phthiriasis, and 
way into the skin, and thus produce so-called “ lice-blains, open or 
closed.” Once admit that the whole structure of these ani- 
mals, in every part from beginning to end, is exclusively calcu- 
lated for blood-sucking habits, then a peculiar disease caused by 
them, such as phthiriasis is described to be, will immediately 
show itself to be an impossible thing, unless we return to the 
ancient notion, which now-a-days is in so little esteem that no- 
body dares to avow it publicly,—viz. that vermin could be ge- 
nerated spontaneously by the formation of cutaneous secretions. 
If, therefore, the name is not to disappear altogether, nothing 
will remain to which it could be applied except such abnormal 
conditions of the skin as, in consequence of its peculiar 
structure and manner of growth, may perhaps develope them- 
selves under continued ill-treatment by blood-sucking animals, 
at any rate when combined with other influences, such as may 
always be supposed to exist in individuals who allow their per- 
sons to serve as habitation and food for that kind of parasite. 
At the same time, the notion of such a disease will presumably 
linger a long while amongst the uninitiated; for imagination, 
which originally seems to have bred this notion as a kind of 
consolation and excuse for the continued existence of these ani- 
mals, will also in future be inclined to stamp the degradation 
as an unfathomable affliction of providence, and to give that 
which is merely disgusting a touch of the sublime by unlimited 
exaggeration. And in this respect it will always be a circum- 
stance of great moment that precisely the most famous and 
mighty men, poets, philosophers, and statesmen, kings and 
emperors, are reported to have died from this direful disease. 
All those who have written on the subject have more or less 
misunderstood Swammerdam’s treatise ‘ Van de ontleeding van 
de Menscheluys” (Biblia Nature, 1. 67); but none of them have 
read it carefully, much less mastered it fully. It is true, how- 
ever, that a superficial abstract of his observations pervaded all 
works on natural history until the year 1839. According to 
this, the mouth of the louse consisted of an haustellum armed 
with hooks and capable of protrusion, from which a much smaller 
sucking-tube could be pushed out: “Os aculeo exserendo” (L. 
Syst. Nat.); “ haustellum retractile, reeurvum ” (Fabr. Ent. Syst.); 
“os haustello antico tubuloso, brevissimo” (Latr. Gen. Ins. et 
Crust.). But when Burmeister (Genera Insector. icon. illustr. 
1838) had published Nitzsch’s posthumous drawings of the 
mouth of the louse (pl. 2. f. 3-6), the following remarkable state- 
ment was made by Erichson in ‘ Archiv f. Naturgesch.’ 1839, 11. 
pale 
“The drawing of the parts of the mouth agrees entirely with the de- 
scription given by Nitzsch in the third volume of Germar’s Magazine. 
