ALOE ALOSA. 



great quantities are annually exported to all the 

 northern parts of the world. In this country almonds 

 rarely ripen their kernels ; the trees being planted for 

 the beauty of their flowers only. They are easily pro- 

 pagated by budding on their own or on plum stoeks. 



ALOE. This is a numerous family of succulent 

 plants, mostly of a half-shrubby description. A few 

 are herbaceous, and all treated as inmates of the 

 greenhouse. Linnacan class and order, Hexandrin 

 Muiiogynia. Natural order, Hemcrocallidea;. Generic 

 character : calyx, monosepalous, tubular, almost cylin- 

 dric, in six divisions ; stamina, six, inserted into the 

 base of the calyx ; stigma, three-lobed ; capsule, three 

 sided, of three places, containing seeds. The south 

 of Africa is the habitat of the aloe family ; and there 

 some of the species grow to the height of fifteen or 

 twenty feet, though by far the greater number are of 

 more humble growth. The leaves are thick, rising 

 out of the embrace of each other ; variegated in co- 

 lour, smooth, or warty, 

 and many are defended 

 by spines as well on the 

 disk as on the edges and 

 p< lints of the leaves. The 

 ilowers are not terminal, 

 but rise from among the 

 leaves laterally, and ap- 

 pear on long spikes either 

 erect or drooping. The well-known drug bitter aloes 

 is drawn from some of the species. Soccotrine aloes 

 were esteemed the best ; but the spicata fig is in 

 every respect equal. The drug is obtained by drain- 

 ing the juice from the dissevered leaves. A. soccotrina 

 is cultivated in the West India islands for the manu- 

 facture of the drug. 



The aloe family was formerly much more numerous 

 than it is now ; many of the species have been re- 

 moved to form new genera, as Pachidendron and 

 Haworthia ; and several have been removed to old 

 genera. They are altogether a remarkable family of 

 plants ; their thick Meshy leaves being in the shape of 

 tongues, cushions, spears, &c. 



ALONSOA(Ruiz, Pavon). A small family of exotic 

 nndershrubs, containing four species, requiring green- 

 house treatment. Linnaean class and order, D'tdynanua 

 A/igio.ipcrnifi. Natural order, Solanecc. Generic cha- 

 racter : calyx, monosepalous, persistent, five-cleft ; co- 

 rolla, monopetalous, irregular, lips turned back, divided, 

 upper divisions short, reflected, the two lateral thrice 

 the size of the upper, the lower largest; stamina, 

 didynamous, declining ; style,longcr than the stamens ; 

 stigma, bifid; capsule, oval. This genus is closely 

 allied to Hcmimcris. 



ALOSA Shad. A genus of abdominal soft- 

 fi nncd fishes, belonging to the Clupeadce, or herring 

 family. The shad genus has been very properly se- 

 parated from the herring and the pilchard, with which 

 it was classed by Linn-.cus ; as they are different from 

 these in appearance and in habit. The herring and 

 pilchard are migratory fishes ; but they migrate in the 

 sea only, and never ascend the rivers above the mean 

 line of separation between the entirely salt water 

 and the entirely fresh, and seldom indeed so far. 

 Shads, on the other hand, ascend the larger rivers 

 into the fresh waters ; and they appear to spawn 

 there in preference, whereas the herrings spawn on 

 the shores of the sea. The herrings, too, come later, 

 or perhaps, with reference to the time of spawning, it 

 is more correct to say earlier. They come in winter 



or even in autumn, and the shads not till April or May 

 The herring fry, or herring " sail," as the countless my- 

 riads of the young of these fishes are called, appear, in- 

 deed, to form much of the food of the shad as it ascends 

 the estuaries ; and the shad is a ravenous fish-eater, 

 which is not understood to be the case with the herring. 

 In its migration it may be said to be intermediate be- 

 tween the herring and the salmon, both in the time 

 and the height to which it ascends the rivers ; and, 

 as is the case with the salmon, it lingers for a consi- 

 derable time in the brackish water, befor6 ascending 

 into the fresh. 



The reason why they linger there is an important 

 point both in the natural history and the economic use 

 of this fish. It is a well-known fact in chemistry, that 

 when two liquids of different densities unite together, 

 there is a want of compcnclration, by which a certain 

 degree of heat is produced, as much as three or four 

 degrees of the common thermometer in the case of 

 sea and river water, supposing that they have both 

 the same temperature previously. At the mouth of a 

 river there is a constant union of this sort ; and 

 though the maximum increase of heat moves a little 

 with the tide, it does not move nearly so far as that 

 does, for the wave of tide flows up the fresh water, 

 and ebbs out a considerable way into the salt. By 

 this means the fishes, when, in their migrations, they 

 resort to the estuaries for the sake of the heat, are 

 not moved like tidal things, but rest in a limited space ; 

 while the water passes and repasses over them, and pro- 

 cures them plenty of food, both in its ebb and its flow. 



While the salmon, the shad, or any other fish hav- 

 ing this migratory habit, remains in the salt water, it 

 does not appear to be capable of breeding, or of 

 bringing forward the roe and milt, so as that they 

 shall be fit for depositing. The same appears also to 

 be the case if the fish remain in the fresh water ; 

 and, besides, they lose flesh in the fresh water. The 

 descent to the sea is thus necessary to restore them 

 to vigour as individual fishes, and the resort to the 

 brackish water is essential to their fertilisation. When 

 they are first met with in the offing of the estuary they 

 are in fine condition as food, and the roes are small. 

 As they linger in the brackish water the roe increases 

 rapidly, and the quality of the fish falls off, though 

 not so rapidly in proportion. When the roe has at- 

 tained nearly its full size, the fishes ascend into the 

 fresh water, gradually falling off in quality, so that 

 those caught in the upland streams and in the 

 brackish water do not appear the same species. The 

 difference is most conspicuous in the salmon, but it is 

 very evident also in the shad ; and even in the her- 

 rings, which do not resort to the brackish water, the 

 first that come are always the best. 



The species of shad best known, and indeed the 

 only one, is the common shad (clupca atom of Lin- 

 naeus), the distinguishing character of which is a. cleft 

 in the snout ; there is also an irregular black spot 

 behind the gill cover, and the mucous ducts on that 

 organ are finely branched. In the warmer parts of 

 Europe (for the shad inhabits more southerly than 

 the herring or the salmon) it attains the length of 

 three feet ; but in our estuaries it rarely exceeds half 

 that length. In Scotland, where it is taken in the 

 salmon nets, though not in any considerable quantity, 

 it is called the. " elf-herring," that is, the plague or 

 pest of the herrings ; and the name is not an undo- 

 scriptive one, as the large herrings disappear before 

 the shad comes, and it eats great numbers of the 



