AGE 



AIR 



tarellus, deliciosus, cinjiamomeus , pra- 

 tcnsis, violaccus. The poisonous 

 kinds have usually a narcotic or acrid 

 odour. 



AGAVE. The Mexican aloe. The 

 juice yields pulque, and a good hemp 

 is made from the leaves. 



AGE OF ANIMALS. For that of 

 the horse, see Horse. 



Age of Neat Cattle. — The age of ! 

 cmcs, oxen, and hulh is known hy the 

 teeth and horns. At the end of about 

 two years they shed their first fore- 

 teeth, which are replaced by others, 

 larger, but not so white ; and before 

 five years all the incisive teeth are 

 renewed. These teeth are at first 

 equal, long, and pretty white ; but as 

 the animals advance in years, they 

 wear down, become unequal, and 

 black. When three years old, neat 

 cattle also experience a considerable 

 change in the structure of their horns, 

 after which period these appendages, 

 like the second or permanent teeth, 

 preserve the same character. Du- 

 ring the first year of the animal's age, 

 two small, smooth, pointed, and neat- 

 ly-formed horns make their appear- 

 ance, attached to the head by a kind 

 of button. This conformation con- 

 tinues during the first three years, 

 after which the button moves from 

 the head, being impelled by a horny 

 cylinder. Thus the horns continue 

 growing as long as the animal lives, 

 as is indicated by the annual joints, 

 which are easily distinguished in the 

 horn, and by which the age of the 

 creature may be easily known, count- 

 ing three years for the point of the 

 horn, and one for each of the joints 

 or rings. Dishonest dealers some- 

 times obliterate these rings by shaving 

 or filing the horns, in order to conceal 

 the age of the beast. — {Johnson.) 



Age of Sheep. — The age of these 

 animals is known by their having, in 

 their second year, two broad teeth ; 

 in their third year, four broad teeth ; 

 in their fourth year, six broad teeth ; 

 and in their fifth year, eight broad 

 teeth before ; after which none can 

 tell how old a sheep is while its teeth 

 remain, except by their being worn 

 down. 

 10 



About the end of one year, rams, 

 wethers, and all young sheep lose the 

 two fore-teeth of the lower jaw ; and 

 tliey are known to want tlie incisive 

 teeth in the ujiper jaw. At eighteen 

 months, the two teeth joining to the 

 former also fail out ; and at three 

 years, being all replaced, they are 

 even and pretty white ; but as these 

 animals advance in age, the teeth 

 become loose, blunt, and afterward 

 black. 



AGI, or AGY. Chilian pepper, 

 Capsicum laccatum. 



AGISTMENT. Payment for pas- 

 turage on another's lands. 



AGRICULTURE. The whole art 

 and science of husbandry. For the 

 history, see Loudon'' s EncycJopcedia of 

 Agriculture. 



AGRIMONY. The genus Agri- 

 mo7iia, perennial, unimportant weeds 

 of small size. 



AGRIONID.E. The family of in- 

 sects called dragon flies (Libellula, 

 Agrion). 



AGRONOMY. The cultivation of 

 land, agriculture. 



AGROSTIS. The genus of bent 

 grasses. They grow chiefly in wet 

 places, and flower late ; most are 

 perennial, stoloniferous, or creeping, 

 and are therefore difficult to extir- 

 pate, and unsuited to rotations. The 

 Agrostes slricta is the red top, or herd 

 grass. A. stolonifera is Richardson's 

 florin, and, when grown in rich, wet 

 pastures, is very superior. 



AIGRETTE. The down or pap- 

 pus of the seeds of compositae. 



AIR. Any gas, but usually the at- 

 mosphere, which see. 



AIRA. The genus of hair grasses. 

 They are perennial, usually grow in 

 wet places, and are of little moment 

 in agriculture. 



AIR CELLS. In plants, enlarged 

 cavities in the cellular tissue, to pro- 

 duce buoyancy in aquatic plants. In 

 birds, membranous cavities commu- 

 nicating with the lungs, and traver- 

 sing all parts of the bird, even to the 

 interior of the bones and quills. In 

 some insects the air vessels are en- 

 larged into cells. 



AIR PLANTS. Those which grow 



