Cactales.J CACTACE^. 747 



considered a modification of structure common to all Orders. Hence the immediate 

 relationship of Indian Figs is neither with Spurgeworts, nor Cassyths, nor Aselepiads 

 nor Asphodels, all of which contain a gi'eater or less number of succulent genera! 

 Through Rhipsahs, which is said to have a central placenta, they seem connected with 

 Purslanes, to which also the curved embryo of the section of Opuntias probably 

 indicates an approach. De CandoUe further traces an affinity between these plants and 

 Ficoids (Mesembryaceae), which correspond in their numerous petals, habit, aiuuilar 

 embryo, and somewhat in plaeentation ; but which have a many-celled fruit, belong- 

 ing to the perigynous rather than the epigynous category. The anatomy of Indian 

 Figs has engaged the especial attention of Schleiden, Miquel, and others, whose 

 observations will be foimd in the places above quoted. One of the most curious 

 circumstances connected with it is that their spu-al vessels arc extremely short, 

 and are formed with a spiral plate of considerable breadth and thickness, instead of 

 a thread. For an elaborate accomat of this Order, see Schleiden's Memoir above quoted. 

 Currantworts, with which Indian Figs were formerly combined, manifestly differ in a 

 large number of points, and especially in their abundant albumen. 



In this covmtry we scarcely know the Indian Figs except as succulent 

 ugly shrubs \vithout leaves, but the Peresldas have leaves of a sufficiently 

 ordinary description, and when old the columnar species form wood of 

 considerable strength. Indeed, according to Air. Hinds (Ann. Nat. Uint. xv. 

 100), Humboldt speaks of a foi'est of such plants, not mere herbaceous 

 species, but tall trees with stems yielding wood suitable for domestic pur- 

 poses. It has been well observed by Dr. Walpers {Repertorium Botanices 

 SystematiccB , vol, 1. p. 269) that the confusion of species and names, in 

 the Order of Indian Figs, is without a parallel, owmg to the negligence or 

 bad descriptions at once of writers, cultivators, and travellers, and that 

 the so-called species are in many cases distinguished by characters of the 

 most trifling natm'e. 



America is the exclusive station of the Order, no species appearing 

 to be native of any other part of the world. In that country they 

 are abundant in the tropics, extending a short distance beyond them, CCCCXCIX. 

 both to the north and the south. De Candolle states that 32'' or SS'^. 

 north latitude is the northern Umit of the Order ; but it is certain that a species is either 

 wild or natiu-alised in Long Island, m latitude 42° north, and that there is anotlier some- 

 where about 49**, in the Rocky Mountains. Those which are said to be wild or natu- 

 ralised in Europe, Mauritius, Arabia, and China, are either species of succulent Spurges, 

 &c., or, if really Indian Figs, have been introduced from America, and having foiind 

 themselves m situations suitable to their habits, have taken possession of the soil like 

 actual natives : in Em'ope this does not extend beyond the town of Fmale, in 44° north 

 latitude. There is no reason for supposing that the modern Opuntia is described in 

 Theoplirastus, as Sprengel asserts ; the account of the fonner writer, as far as it applies 

 to anything now known, leather suits some tree like Ficus religiosa. Hot, dry, exposed 

 places are the favourite stations of Indian Figs, for which they are peculiarly adapted, 

 in consequence of the imperfect evaporating pores of their skm ; a circumstance which, 

 as De Candolle has shown, accounts for the excessively succulent state of theii- tissue. 

 For geogi-aphical observations see Martiics in Ann. Sc. 2. ser. 2. 110. 



The fruit is very similar in its properties to that of Currants, in some being refresh- 

 ing and agi'eeable to the taste, m others mucilagmous and insipid. ]\Iany ai-e valued as 

 palliatives of intennittent and biUous fevers, in consequence of their refreshmg subacid 

 juice. The finiit of Opuntia vulgaris has the property of staining red the m-ine of those 

 who eat it. That of 0. Tuna is of the richest carmine, and forms a valuable pigment, 

 employed at Naples as a water-colour. The juice of Mammillaria is remarkable for 

 bemg slightly milky, and at the same time sweet and insipid. Rhipsalis pachyptera has 

 not only the succulent finiit of the Order, but is bruised and used as a fomentation for 

 ill-conditioned ulcers.— ilfar^ms. The fruit of Pereskia aculeata is pleasant and expec- 

 torant. The great fleshy stems of some Mexican species arc eaten by cattle ; a ^•ery 

 remarkable specimen of this kind is described by Sir. W. Hooker, in the Oardaurs 

 Chronicle, 1845, p. 132. Mr. Darwin found that a species of Cactus was one ot the 



principal kinds of food of the land-tortoises in the Gallapagos. 



Fig. CCCCXCIX.— Flat-threaded spiral vessels of Indian Figs. 



