lit 



ALQX, FOSSIL. 



AI.I.ll.'ATiii:. 



jVestoeMOT are chiefly found in fresh-water streams and damp 



...-!,. 



re amount the lowest form* of the Alfa. They 

 of globose or elliptical cells, which are more or lew distinct, 

 and are collected together by mean* of a string-layer into a frond. 

 The genus rVofeeoenu ha* only one species, the P. niralit. This little 

 plant ha* gained a large share of attention on account of its being 

 upposed at one time to be the cause of red now. Now however the 

 animal kingdom has put in a claim for a share in the production of 

 this phenomenon. [Sxow, RKO.] Moat of the specie* of 1/amalocan 

 are of a red colour, and give an appearance like that of blood to the 

 rooks on which they grow. These appearance* have often been 

 regarded with a superstitious eye, and looked upon as warnings or 

 omen* from Heaven. One of the specie* of PaintMa, the P. erumta, 

 ha* a dark blood-red colour, and on that account haa been called 'gory 

 dew.' It occurs on white- washed walls, especially in damp cellars ; 

 and in mich situations has sometimes given occasion for alarm, ou 

 account of Ha having the appearance of stains of blood. The other 

 pecies of Palmetla have various colours, as yellow, green, and black. 

 They are found in fresh water streams and on rocks on the sea-shore. 



(Harvey, Itrituk Marinf Alga; Hooker, Brituh Flora; Agardh, 



Sjtfda Algantm ; Greville, Alyir Britannicir ; Lindley, Vegetable 



Xiitgdom; HasU, Fmk-Water Alga; Burnett, OutUttet of Balmy.) 



ALO^E, FOSSIL. The remains of sea-weeds in a fossil state are 



lea* common than their probable abundance in the ancient ocean and 



the generally marine origin of the strata might have led to suppose. 



This arise* perhaps from the cellular texture and destructible nature 



of t he marine plant*. Trace* however of several genera occur iu 



Silurian, Carboniferous, Lioasic, Oolitic, Cretaceous, and later deposits. 



ALGAROBA BEAN. KERATONIA.] 



ALHAGI (from the Arabic Affkul or Algol), a genus of plants 

 belonging to the natural order Leguminottr. The species are under- 

 shruba or herbs with simple leaves and minute stipules. The flowers 

 are red, and disposed in racemes along the peduncles. 



A. Manronim is a native of the deaerts of Egypt, Syria, Mesopo- 

 tamia, and other countries of the East. This plant yields a species of 

 manna which is called Tmngibin or Terengabin. It is chiefly gathered 

 in the neighbourhood of Tanris where the plant grows abundantly. 

 The nanna is a natural exudation from the leaves and branches of 

 the plant, and is most abundant during -hot weather. In Arabia it is 

 supposed that the manna foils from heaven on the plant. It first 

 appears in the form of a small drop as of honey, which goes on 

 increasing in size till it is about as large as a coriander seed. The 

 manna yielded by this plant does not appear-to be imported into this 

 country. It is principally made use of at the present day in Persia, 

 ami is known by the name of Persian Ifannq. It is employed as food 

 for cattle. Two other species, A. Cameimum and A. Nipaulennt, ore 

 described by botanists, and cultivated .in the greenhouses of this 

 country. Ttey also yield manna. 

 ALISMA. |Auu*CEiE.i] 



Al.ISMA'CK/K, a natural order of plants belonging to the class 

 Endoyent. It is known from all the other orders of the same division 



by its genera having the 

 sepals and petals perfectly 

 distinguishable from each 

 other both ; in colour and 

 situation, and by their 

 carpels being extremely 

 numerous. In many points 

 they approach very nearly 

 to the Crowfoot Tribe 

 (Kanuneuiaeeif), from which 

 the structure of their 

 vmlii .. --ir endoge- 



growth. dill- 



All the species are aquatic 

 plants, with rather broad- 

 ribbed leaves and white 

 flowers. They appear to 

 be destitute of any active 

 .properties, except a slight 

 degree of acridity, which 

 > however does not prevent 

 tin- rhizomaof some of them 

 from being eaten in China. 



The orAcf receives its 

 name from the genus A litmn, 

 one species of which, 



4 1 "i"" Plan/ago, a common 

 Great Water FUataln (4/ Plant,,,). wjl( , |JaIlt of Jj,^ ^^ 



(n wet ditches and by river aides, has had the unfounded reputation 

 of being a cure for hydrophobia. Its powdered root is given in doses 

 of from half a drachto to a drachiu, either infused in wine or mixed 

 Ulth syrup. 



ALKANKT. [AjiCHCSA.1 



AI.LACITK, iu Mineralogy, is a variety of the tri-ailicate of 

 of Manganese. 



A I, I. A LITE, in Mineralogy, a variety of JHojuulf or 1'ynucnn. 



Pnoua 



ALL AMANDA, a genus of plants belonging to the natural order 

 Apocynacta. It was named after Frederick Allamand, a surgeon h 

 travelled in Guiana, in 1760, and afterward* in Ruaua. He was a 

 oomepondent of Luinaraa. 



The specie* of this genus are shrub* yielding a milky juice, with 

 vert icillate leaves, and many-flowered peduncles of large yellow flower*. 

 They are worthy of cultivation on account of the beauty of their 

 flower* and foliage. They are all native* of South America, and when 

 cultivated require a strong moist heat to make them flower freely. 



An infusion of the leave* of A. calAarlica is said to act as a 

 powerful purgative, and an overdose to produce poisonous effect*. 



ALLAN1TE, in Mineralogy, a aynonyme of OrCAtfe, which is one 

 of the silicates of cerium mixed with other substances. [OKTUITK.] 



ALLIGATOR, a name originally given by the British Colonist* of 

 the Southern States of the North American Union, to a large species 

 of reptile closely resembling the Crocodile of Egypt, but win. h 

 modern researches have shown to possess characters genetically differing 

 from those of that animal. The word is supposed to be a corruption 

 of an old Indian name. According to its modern acceptation among 

 zoologist*, the name is no longer confined to the specie* most 

 commonly found in Carolina, Louisiana, and the other Southern 

 States of the Union ; but it is applied generically to all the other 

 American species which agree with it iu its most prominent and 

 influential characters, and which have been called Caymans, Jacare*, 

 &e., by the Spaniards, Portuguese, and Indians of South America. 

 The characters which are proper to the Alligators, and by which tlicy 

 are distinguished from the Crocodiles of the OM World, are by n 

 means of such importance with respect to the influence they may be 

 reasonably supposed to have upon the habits and economy of these 

 animals as to warrant the formation of these reptiles into a dieting 

 and separate genus : their manners and habits are precisely those of 

 the true crocodiles, and if they differ in certain minor details of 

 structure, this difference should be considered not as a generic charac- 

 ter, but as purely specific. 



M. Cuvier thus distinguishes the Alligators from the true Crocodiles : 

 "The alligators have the head less oblong than the crocodiles; its 

 length is to its breadth, measured at the articulation of the jaws, as 

 three to two ; the teeth are unequal in length and size ; there are at 

 least 19, sometimes even as many as 22, on each side in the lower juw. 

 flnd 19 or 20 in the upper' The front teeth of the under jaw pierce 

 through the upper at a certain age, and the fourth from the front, 

 which <ire the longest of oil, enter into corresponding holes of the 

 upper jaw, iu which they ore concealed when the mouth is closed. 

 The hind legs and feet are round and neither fringed nor pectinated 

 on the sides; the toes ore not completely webbed, the connecting 

 membrane only extending to their middle; and finally, the po.-t- 

 orbital holes of the cranium, so conspicuous in the true crocodiled, 

 are very minute in the alligators, or even entirely wanting." The 

 Crocodiles, properly so called, ou the contrary, have the head at least 

 twice as long as it is broad; Ifi teeth on each side of the lower jaw, 

 and 19 on each side of the upper. The incisor or front teeth, OH in 

 the alligators, pierce through the upper jaw, at a certain age, but the 

 fourth or largest of the lower jaw, instead of being received into :i 

 corresponding hole of the upjier, |8aes into a notch on each side of 

 it ; and finally, the hind foot are bordered by a denticulated fringe, 

 and the toes are completely ' united toy a swimming membrane. 



The characters here reported as peculiar to the alligators and croco- 

 diles respectively, ore evidently not of sufficient importance to exert 

 any very sensible influence upon 'their general economy. Of the 

 characters and organic modifications -wliich they possess in common, 

 the principal is the long taper tail, strongly compressed on the sides, 

 and surmounted towards its origin with a double series of keel-shii]>e<] 

 plates, forming two upright denticulated crests, which, gradually con- 

 verging towards the middle of the tail, there unite and form a single row 

 to the extremity. Its great size, and laterally-compressed form, render 

 the tail an organ of the utmost importance to the crocodiles and 

 alligators : it is true that its weight materially impedes their motions 

 on dry land, but it is a most powerful instrument of progression in the 

 water, and influences the aquatic habits of these animals much more 

 than their webbed feet The latter character, indeed, is comparatively 

 'if little weight : the hind feet are only used to assist the progression 

 in slow and gentle motion, but in all midden untl violent ;uti.iii- tin 

 tail alone in tlie aetive instrument; and even when the animal in 

 surprised on land, as we are assured by Adansou, it becomes a 

 powerful wut|ioii of offence. The compression of the toil i 

 peculiar among reptile* to crocodiles, though so powerfully influencing 

 their habits ; but the second character which in common to the entire 

 genus, namely, the palmated or senii-paiinatod hind feet, is exhibited 

 I >v no othergeini* of reptiles, though all ore more or less addicted to an 

 life. Thin fact sufficiently demonstrates the small influence 

 which the j>almntl form .of the extremities .exerts upon the economy 

 of these animals in general. Still thin character is by no means devoid 

 of MII]. ortance, though in proportion to its utility in aquatic progression 

 it renders the terrestrial motions of the animals extremely slow and 

 :ikw;ird: mid this effect is still further increased by die length .T.I 

 of the toil at one end, and by the anatomical structure of the 



