PREFACE. Vll 



previous labours have gained from an indulgent public, 

 at once to display his gratitude for the past, and his 

 zeal to distinguish himself still farther in a very useful, 

 though unassuming, department of literature. 



When he recalls to memory the numerous instances 

 in which he has already been a candidate for public 

 patronage, he almost shrinks back from future appeals 

 to its indulgence ; but the reflection that, if he has not 

 been able to increase the fund of knowledge by any 

 large accessions of his own, it has, at least, been his 

 good fortune to render the services of others more 

 popular, and present them to British youth divested 

 of every forbidding incumbrance and every dangerous 

 admixture, encourages him to persevere; and the re- 

 ception of his labours persuades him that they have 

 not been wholly in vain. 



He earnestly trusts that this apology will be accepted 

 in the spirit by which it was dictated ; and now takes 

 the liberty of adverting to the object of his immediate 

 performance. 



Natural history, during the present auspicious reign, 

 has been cultivated with such success in all its branches, 

 that the superficial observer might suppose it to be 

 exhausted. Those, however, who have made the 

 greatest advances in this delightful study will own 

 themselves still comparatively ignorant of the laws of 

 nature, and the links which unite her multifarious pro- 

 ductions. The lover of system arranges only, and 

 describes external appearances ; while the philosophic 

 inquirer throws off the trammels of scientific formality? 

 and, looking at qualities alone, envelopes his disco- 

 veries in an unformed mass of heterogeneous matter 

 from which common industry cannot extricate them. 



All ranks, however, and all ages, show some predi- 



