PREFACE. XI 



inaccurate contributions to periodical publications. Dr Samuel Johnson, 

 the lexicographer, remarks of the singularities of a cavern in the Hebri- 

 des, that he there saw what he had never seen before, " limpets and mus- 

 sels in their natural state,"^an example of how little the most familiar 

 objects are known ! 



If the naturalist expects ready confirmation of his discoveries or ob- 

 servations, he must occupy himself with subjects of easy acquisition, — with 

 those which are not rarities. The common store of knowledge might be 

 also enlarged by bestowing more attention on the productions of our own 

 immediate districts, instead of seeking after those at a distance. Things 

 common to us, may be to others very rare. 



Some of the most desirable animals are frequently of the most diffi- 

 cult attainment. But the majority of living creatures are local : Food, 

 soil, and climate, have spread them over the earth, and lodged them amidst 

 the waters. A modern French author expresses his surprise, that the 

 scarcity of a certain zoophyte, plentiful in his own country, should have 

 embarrassed an English naturalist. If I mistake not. Professor Delle 

 Chiaie, a learned Italian, affirms, that, from the Bay of Naples, he had ob- 

 tained 2000 Holothuriae, — an animal so rare in most of the British seas, 

 that very few of our naturalists can say they have ever seen it alive. Though 

 having myself been more fortunate, for at least 150 of different species 

 have fallen into my possession, some of them surviving for years, it will be 

 seen in the course of these Memoirs, how little information I can offer on 

 the subject beyond those faithful representations after Nature, which I can 

 find nowhere else : — Or how meagre my narratives of the Lohularia, 

 Terebella, Amphiirite, and many others, tliough year after year was 

 anxiously devoted to enquiries regarding them. 



Of various other animals, I can do scarcely more, if so much, as 

 skilful authors have left nothing important, besides, to illustrate their his- 

 tory. It is by uniting fragments that regular narratives are completed. 



The sedulous naturalist must advance with a steady pace ; he is not 

 to be deterred from description, because unable to compose a dissertation : 

 nor abandon his dissertation, from wanting illustrative views at the mo- 

 ment to confirm it. He must often renew his task, though often inter- 



