CLASSIFICATION AND NOMENCLATURE. 31 



kingdom ; but in one division (Acrita — comprising polypes, 

 infusoria, animalcules, sponges, &c.) no traces of nerves have 

 hitherto been discovered. The best characteristic of the animal 

 kingdom is the possession of a mouth or aperture through 

 which food is received, and a stomach in which it is digested ; 

 and this includes all the organised beings which have ever been 

 considered by naturalists to belong to the animal kingdom, 

 except the various kinds of sponges. My limits are prescribed, 

 so that further observations must be dispensed with here. But 

 the following beautiful remarks by Mr Rymer Jones so admir- 

 ably illustrate the difficulty of drawing an exact line between the 

 animal and vegetable kingdoms that I gladly conclude in his 

 words — " Light and darkness are distinct from each other, and 

 no one possessed of eyesight would be in danger of confounding 

 night and day ; yet he who, looking upon the evening sky, 

 would attempt to point out precisely the line of separation 

 between the parting day and the approaching night would have 

 a difficult task to perform." 



Thus it is with the physiologist who endeavours to draw the 

 boundary between these two grand kingdoms of Nature ; for so 

 gradually and imperceptibly do their confines blend, that it is at 

 present utterly out of his power to define exactly where the 

 vegetable existence ceases and animal life begins. And South ey 

 beautifully says of night and morning when they meet — 



" The nightingale not yet 

 Had ceased her song, nor had the early lark 

 Her dewy nest forsaken." 



Therefore, when the exact confines of day and night can 

 scarcely be defined, and when it is impossible to define the 

 exact limits of two such widely different organizations as the 

 animal and vegetable kingdoms, how can we define the exact 

 genus, family, or order of a class of creation so varied — yet so 

 much alike in their various affinities — as the birds? Some 

 ornithologists think that the imcard machinery — the unseen 

 entrails — are the best criterion to regulate their order. Others 

 deem the plumage ; some the shape of the bill ; others the toes, 

 as in the scrapers — like the hen ; or in the web feet for swim- 

 ming — like the duck. 



But the science of Nature is so very perfect and complete 

 that it does not matter where we begin our study, for we will 

 find affinities, order, and perfection everywhere, whether it be in 

 the hen scraping on a dunghill, or in the eagle soaring over a 

 mountain. Therefore, as none are progressive in intellect, like 



