94 



the roads, and it is no uncommon occurrence to 

 find them similarly used in some parts of Somerset- 

 shire, Gloucestershire, Yorkshire, and other counties, 

 where they are abundant in the lias and inferior 

 oolite formations. Large and fine specimens, in some 

 of these counties, may often be observed built into the 

 fronts of houses, forming an elegant natural ornament, 

 called by the peasants petrified snakes, no doubt from 

 the remains of a superstitious legend recorded in 

 Camdcn's Britannia, exhibiting one of the many effects 

 of our ancestors' credulity and ignorance, particularly 

 in geology and natural history. He writes, " Upon the 

 same river Avon, which is the boundary here between 

 this county (Somerset) and Gloucestershire, on the 

 western bank of it is Cainsham (now Keynsham), so 

 named from Keina, a devout British virgin, whom 

 many of the last age, through an over-credulous tem- 

 per, believed to have changed serpents into stones, 

 because they find sometimes in quarries some such 

 little miracles of sporting nature. And I have seen a 

 stone brought from thence winded round like a ser- 

 pent, the head whereof, though but imperfect, jutted 

 out in the circumference, and the end of the tail was 

 in the centre, but most of them want the head." 

 Walter Scott has happily adapted this legendary tale 

 in one of his elegant poems. 



These shells vary from microscopic diminutive- 

 ness to the enormous size of two feet and a half in 

 diameter, entitling them to play their part with the 

 ichthyosaurian, pleosaurian, and other gigantic crea- 

 tures of a former world, whose race has passed away, 

 but whose stupendous vestiges excite in the contem- 

 plative minds of us little beings awe and wonder at 

 the vastncss of creation, and the immeasurable gran- 

 deur of the Creator. See SALGRAM STONE. 



AMMYRSINE(Pursh). A genus of plants of one 

 species only ; a North American under-shrub, belong- 

 ing to the class and order Dccandria Monogynia, and 

 to the natural order Ericcae. Generic character : calyx 

 divided into five lance-shaped parts; petals of the 

 corolla five, oval, obtuse, and spreading ; stamens 

 inserted in the receptacle, filaments like hairs, longer 

 than the corolla ; anthers egg-shaped, double ; style 

 round ; stigma truncated ; capsule three-celled and 

 three-valved, seeds small and oval. This American 

 plant is nearly allied to the Ledums, Rftodoras, and 

 other beautiful shrubs from the same quarter of the 

 world. In this country they are cultivated alike, and 

 always in beds or borders of moor (not peat) earth in 

 shadv situations. 



AMOMUM. A genus of plants consisting of thir- 

 teen species, all inhabitants of the warmer latitudes of 

 the globe. They belong to the first class and order of 

 the Linnajan system, and to Scitamincce of the natural 

 system. The generic character consists in the inner 

 limb of the corolla having one lip, another with an 

 entire or two-lobed crest, seeds with an arillus. 

 This genus is allied to the ginger and turmeric fami- 

 lies, and partakes of their aromatic and colouring 

 properties. The A. cardamomum, and A. grana Parodist 

 are both extensively used in medicine, and others are 

 useful in the arts.- 



AMPELIDE^E. The forty-ninth order of the 

 natural system. It comprises four genera, and fifty- 

 three species. The grape vine belongs to this order, 

 and gives a value to the whole. Its congeners are 

 as follow, viz. cissits, Lcea, and ampifapsis, the genus 

 which gives name to the order. With the exception of 

 the vine, all the plants belonging to this order are of 



A M M Y R S I N E-A M P H I B I A. 



little interest. The prevailing habit of the order is a 

 long dangling growth of stem, thyrsus oi simple 



VITIS VIMFBRA. a, a bunch of the flowers 5 b, flower before 

 expansion ; c, flower expanding; d, stamens, pistil, and germ ; 

 e, vertical section of the pistil and germ ; /, fruit; K, horizontal 

 section of the ovary ; h, vertical section of the fruit, showing the 

 position of the seeds. 



colourless flowers, or tendrils opposite the leaves, and 

 yielding bunches of berried fruit. 



AMPELOPSIS (Michaux). A genus of North 

 American climbing and shrubby plants, consisting of 

 four species. They belong to the fifth class and first 

 order of Linnaeus, and to the natural order AnipclidecB. 

 Generic character : calyx entire ; petals cohering at 

 the end, withering ; stigma headed ; ovary immersed 

 in the disk, two to four-seeded. The A. quinauefolia 

 is a useful plant for hiding naked buildings, or forming 

 shady bowers, or summer screens in dressed grounds. 

 It grows rapidly and needs no nailing up against 

 walls, it being supported by its own tendrils. 



AMPHIBIA. The third and last of the three 

 groups into which Cuvier divides his sub-order Cur- 

 nivora, propejly so called ; that is, mammalia which 

 prey upon vcrtebrated animals. 



The term amphibia is rather objectionable, unless 

 received with some explanations. The old accepta- 

 tion was, that animals to which the name applied, 

 were supposed to be capable of performing all 

 the functions of life either on land, in the air, or 

 under the water ; but there is no known animal that 

 can breathe in the free air and also in the water ; 

 and, from the nature of the two fluids, as well as from 

 the difference of the organs by which they arc 

 breathed, there is every reason to conclude that there 

 can be no such animal. Cellular lungs, into which 

 air is received, and fibrous gills, among the fringes of 

 which the water plays, are so perfectly distinct, and 

 each is so well and so solely adapted to its own pur- 

 pose, that it cannot be made to perform the function of 

 the other. The introduction'of even a very small por- 

 tion of water into the lungs of an air-breathing animal, 

 would, in all the cases with which we are acquaint rd, 

 be speedy and almost instantaneous death ; and there 

 is not an animal which breathes water which is not 

 thrown into convulsions the moment that its gills are 

 exposed to the air. Some lunged animals can, no 

 doubt, remain a considerable time in the water, with- 

 out access to the air.and some gillcd animals can live 

 for a considerable time out of the water ; but neither 

 the one nor the other so lives because it can breathe 

 under the altered circumstances. On the contrary, it 

 survives merely because it can live for a time without 

 breathing ; and the attempt to breathe the fluid for 

 which it had not the proper apparatus, would occa- 

 sion instant sickness and speedy death. 



There are thus no amphibia, in the literal sense of 

 the word, no animals which, 



" As some rats, of amphibious nature, 

 Are cither for the land or water." 



