246 PARASITES. 



CHAPTEK V. 



PARASITES. PLATES LVL, LVII. 



MANKIND, inflated by pride and folly, vainly suppose that, because 

 the beneficence of Heaven has bestowed on them senses to observe, and 

 reason to judge, they can determine the cause and the use of every thing 

 presented to their view. 



How great is their error ! they ought rather to bow themselves in 

 the humility of ignorance. 



Their total existence is divided into periods of pleasure and pain. 

 But although we may plead the Divine favour, so eminent for protect- 

 ing the tenants of the globe, how shall we account for the subsistence of 

 torment ? Could it be that sensibilities and susceptibilities are inseparable 

 from animated matter ? 



1. CALIGUS CURTUS. Plate LXVI. fig. 1, enlarged. 



This is one of those plagues which Nature, for hidden purposes, 

 permits to exist for the annoyance of living creatures, a persecuting, 

 small, but deadly enemy to those ten thousand times larger than itself. 



Perhaps I should premise, that although the general outline of the 

 Caligus is sufficiently exposed by a simple lens, it is scarcely practicable 

 to ascertain the detail of the parts of the living specimen by any auxiliary. 

 These being chiefly visible from below, this great difficulty originates 

 from position, tenuity, proportions, and confusion of the principal organs, 



