AXIS. 



plants in damp mow, be found them root* had a tendency 

 to come to the surface toward* the light. Not only U thin the CMS, 

 but the colourless item* of such plant* u Sagittarta taytltifulia are 

 known to assume the direction* of roots. In this plant " ahoots are 

 produced from the axilla of all the radical leave* which grow at the 

 bottom of the water. Theae shoot* hare their poinU directed towards 

 the sky, like those of all vegetables. The young stems which are 

 produced by these shoots are entirely colourless, like roots ; and 

 instead of taking a direction towards the sky, as coloured stems would 

 do, they lead downwards, pointing towards the centre of the earth. 

 This subterranean stem next takes a horizontal course, and does not 

 assume any tendency toward* the sky until the points become green." 



(Meyen, Pjtanten-Pkytioloffie ; Lindley, Jntrv<l action to Botany ; 

 Dutrochet, Ann. del Seimea .\atnnllrt, xxix., 1833.) 



AXIS, a species of Indian Deer. The word is also used genetically 

 to denote a small group or sub-genus of solid-horned ruminants, pre- 

 senting the same characters and inhabiting the same climate as the 

 Common Axis. [CEKVUXC.] 



A'XIUS, a genus of Long-Tailed Decapodous Cruttacea, founded by 

 Leach on Aj-itu tlirkynekut, which is about 3 inches or 34 inches in 

 length, and rarely found on our coasts. It has been taken near Sid- 

 mouth and Plymouth. Desmarest, with much reason, considers this 

 genus entirely artificial ; and thinks that it ought not to be separated 

 from Callianatta. [CALUANASSA.] 



AKoLOTL (Gyrinui, Hernandez and Shaw), a genus of Amphibia 

 belonging to a group called Perennibranchiate, as they retain their 

 gills throughout life. They are distinguished from other genera of 

 the same family by having four feet furnished with four toes before 

 and five behind. This group contains the genera Axolota, .I/, m,- 

 branchvt, Proteut, and Sireniu ; and comprises animals which possess 

 at the same time both lungs and gills, and which are consequently 

 organised to live either on land or in water. [AMPHIBIA.] 



The Axolotl was the earliest observed of these remarkable animals. 

 At the period of the Mexican conquest the Spaniards found this animal 

 in great abundance in the lake which surrounded the city of Mexico, to 

 the inhabitants of which capital it then furnished, as it still continues 

 to furnish to their successors, an agreeable and much-esteemed article 

 of food. Hernandez, who seems to be the first writer who actually 

 described the Axolotl, expressly mentions it having been thus used 

 by the ancient Mexicans ; and adds that the flesh was considered as 

 an aphrodisiac, that it was wholesome and agreeable, and tasted not 

 unlike eeL Succeeding authors, without taking the trouble of 

 observing for themselves, were content to copy what Hernandez had 

 said before ; but distorting his short description by absurd comments 

 of their own, and adding the figures of far different species, the whnlu 

 subject became at length involved in such inextricable confuxion that 

 finally all memory of the Axolotl was lost, or the animal itself con- 

 sidered as a fictitious being. The late Dr. Shaw however, who received 

 a specimen of the animal direct from Mexico, recognised in it the 

 Axolotl of Hernandez, as is proved by his having used the generic 

 term Gyrima in his account of it published in the ' Naturalist's Mis- 

 cellany,' which had been originally applied to it by its first describer, 

 though Baron Cuvier seems disposed to deprive the British naturalist 

 of this credit, and to ascribe the sole honour of re-discovering the 

 Axolotl to Baron Humboldt. It is indeed true that Dr. Shaw subse- 

 quently described the same animal in the third volume of his 'General 

 Zoology' under the very different name of Siren pitciformi* ; but this 

 only proves that he considered it, as Baron Cuvier was himself 

 afterwards inclined to do, not as a perfect animal, nor in fact as the 

 type of a new genus, but rather as the immature state of some species 

 belonging to a genus already known. To Baron Cuvier himself 

 however we are indebted for the complete description and elucidation 

 of the form and organic structure of this curious reptile. Two 

 specimens brought by M. Humboldt from Mexico were submitted to 

 the examination of the French naturalist, whose researches on the 

 subject of their anatomy, compared with that of the kindred genera, 

 are recorded in his ' Recherche* sur les Reptiles Douteux,' inserted 

 in the zoological part of Messrs. Humboldt and Boupland's Travels. 

 A detailed examination of all the Batrachiau Reptile*, and more parti- 

 cularly a careful investigation into their anatomical structure during 

 the tadpole ctate, and the gradual change which they undergo in 

 passing from this state to their mature and perfect form, led Baron 

 Cuvier to establish as an unquestionable fact that certain of these 

 niml retain both lungs and gills throughout the entire |>eriod of 

 t)i<-ir existence; but whiUt ho unhesitatingly announced this fart with 

 regard to the Siren and Proteus, he was disposed to consider the 

 Axolotl as the tadpole of some of the larger species of American 

 salamander* an error induced as well by the general similarity which 

 these animal* bear to one another as by the immature age of the 

 specimen* of the Axolotl w In. h were submitted to his observation. 

 Succeeding naturalist* adopted M. Cuvier'* views ujion this subject; 

 but that great zoologist himself subsequently altered his original 

 opinion, and candidly confesse* in the second edition of the ' Kegne 

 Animal ' that the concurrent testimony of all original observer* over- 

 balance* the mere deductions of the physiologist, however plausible 

 or apparently well founded. 



The generic characters of the genus Axolotl, Cini.-r i.l.r.jfo*, Owen, 

 Oynniu, Hernandez), in addition to those above mentioned, consist 



AZA SM 



in having the gill* formed of three long ramified or branch-like pro- 

 cease* on each aide of the neck, four toes on the anterior extremities 

 and five on the posterior, and teeth in the vmer as well as in both 

 jaws. The tail u compreased on the aides like that of the common 

 Water-Newt (Salamtuidra palmala), and surrounded both on the upper 

 and under surface* by a thin erect membranous fin, which U prolonged 

 upon the back, but become* gradually narrower a* it approaches the 

 shoulder*, between which it finally oeaaea. The head is broad and 

 flat; the none blunt; the eye* situated near the muzzle; the tail 

 nearly as long as the body ; and the toes unconnected by intermediate 

 membrane*. The singular form of the gills will be beet understood 

 from the accompanying figure, which represents the under jaw and 

 throat of the animal a* seen from beneath. 



Axolotl (Oyrintu rdula, Hernandez). 



The Axolotl of the Mexican* {(,'i/riniu alula, Hernandez), when 

 full grown, measures about 8 or 9 inches in length ; its ground colour 

 is a uniform deep brown, thickly mottled both on the upper and under 

 surfaces of the head and body as well as on the limbs, tail, and dorsal 

 and caudal fin*, with numerous small round' black spots. The head 

 and body are larger and broader than in the generality of reptiles, 

 and but for the long tail which terminates the latter the whole animal 

 might be not inaptly compared in form to a large frog ; the gills are 

 prolonged into three principal processes, with iiumeroui smaller 

 ramifications from the sides of each, the whole being as long as the 

 fore legs, and resembling three small branches ; the legs are short, 

 though fully developed ; and the toe* are long, slender, separate, and 

 without claws. The communications which open from the gills into 

 the mouth are four in number, and of a size considerably larger than 

 those of the kindred genera ; they are covered externally by a species 

 of operculum formed by a fold in the akin of the head. 



The Axolotl is very common in the lake of Mexico, and, according 

 to Baron Humboldt, likewise inhabit* the cold waters of mountain- 

 lakes at much greater elevation above the level of the sea than the 

 plains Burr, miuling that city. It in c.imm.mly xold in the markets of 

 Mexico, and^esteemed a luxury by the inhabitant*. It is dressed 

 after the manner of stewed eel*, and served up with a rich and 

 stimulating sauce. 



Professor Owen has described a second species under the name of 

 Axvlotti mactil '<'>'. \\ In.-h also is an, inhabitant of Mexico. 



AVK AYK I'miKoMYS.] 



AYMKSTKV I.IMIXK'VK, one of the calcareous bands in the 

 Upper Silurian series which has been produced by coral and shell 

 accumulations amidst the masses of argillaceous sediments. It is not 

 traceable beyond the districts of Lvidlow, Abberley, Mahrni. W....I 

 hope, May Hill, and Usk. It is partially characterised by Pentamcnu 

 Kmigi 



A /.A 'LEA, in Botany, is the name of a genus belonging to the 

 natural order Eritamr, and consisting of shrubs remarkable for the 

 and fragrance of their flowers; on which account they are 

 very generally cultivated in Hum].,.. P.y mine botanist* the genus is 

 esteemed the same as Rhododendron, in which it is accordingly sunk ; 

 and it must be confessed that it i difficult to point out any | 

 character ex<-.-|.t tin- thin and generally deciduous leaves by which 

 iTin be ilintiiiKi:' 



The forms of Azalea may be reduced to four principal heads, to one 



