XIV PREFACE. 



ment of its office, no rational being can for an instant 

 doubt. Therefore, if we cannot in every instance see the 

 immediate end and object of their existence, it is surely 

 more becoming our humility to admire in ignorance the 

 wisdom of God in the works of creation, from a conviction 

 that, that which is is right, than vainly endeavour to scru- 

 tinize or criticise the individual links of that chain by which 

 all nature is kept in harmony and order ; since the smallest, 

 or the most loathsome creatures to human conception are 

 alike to that Being, " Who giveth food to all flesh, for his 

 mercy endureth for ever." The habits or history of the 

 intestinal worms are, perhaps, equally unpleasing or dis- 

 gusting to the partial admirers of nature. Yet by the la- 

 borious investigations and patient research of Rudolphi, 

 993* species of Entozoa have been described in his im 

 mortal Entozoorum Synopsis, by which he has erected for 

 himself an imperishable monument, shewing that to a man 

 of such gigantic powers of mind, whose studies embraced 

 nearly every department of science, the noxious and obscure 

 claimed his especial attention, well knowing that it was the 

 same, whether with devout awe we contemplate the spanless 

 arch of Heaven, lit up with countless myriads of distant 

 glittering worlds, and endeavour to trace the laws by which 

 they are governed and guided through the vast of space, or 

 reduce our investigations to the structure and habits of those 

 humble semi-motionless beings whose dwelling-place is cast 

 in the Hepatic cells, or Cerebral sinuses of the sheep, the 

 eye ball of the Perch, or the 20 species which infest almost 

 every portion of the human frame,f all, and each alike dis- 



* Linnaeus had indicated only 11 species of intestinal worms in the 12th 

 edition of his Syst. Nat. Gmelin in the 13th edition 299. Zeder. 391. Ru- 

 dolphi's first great work on intestinal worms, Entozoorum historia naturalis, 

 contains descriptions of 603. 



t More than 20 of these pestiferous creatures that attack man have been 

 enumerated, some penetrate into the very seat of thought, (Echinococcus 

 Hominis,) others disturb his bile, (Fasciola hepatica,) others circulate with 



