Cactuses have many uses aside from their beauty and curiousness. Very many of the species produce edible fruits, and the time will undoubtedly come when some of them will be grown for their fruits. The natives in the cactus regions lay great store upon the fruits of some species. The great Cereus giganteus produces an edible fruit which the natives gather by the use of long poles. The fruit of Cereus Greggii is shown in Fig. W. This fruit attains a length of an inch and a half, and is edible. The edible fruits of various opuntias, particularly of the Indian Fig (Opuntia Ficus-Indica, Fig. R, page 471) are well known. Most of them are known as prickly pears, from their pyriform shape C. R. Orcutt, a California naturalist, writes recently to Garden and Forest that the manufacture of syrup from the fruit of the opuntia may at no far distant day become an important industry in southern California. Opuntia Ficus-Indica , or Indian Fig, O. Tuna (Fig. T), and O. Tuna-manse have become naturalized around the old Californian missions. They are natives of Mexico and make rank and rapid growth.

The juice of the fruit which these plants produce in great abundance may be extracted in a cider press like the juice from apples, and boiled down to a fruity syrup indistinguishable from that manufactured from the watermelon. Excellent vinegar may also be made from the juice. In Mexico these cactuses are extensively cultivated for their fruit".

Some of the opuntias have long been used for hedges, particularly the Tuna. But the most important use of cactus plants is in the growing of the cochineal insect. This insect is related to the scale insects. It is a native of Mexico and Peru. As early as 1518 it was introduced into Europe. In its native country it undoubtedly feeds upon several species of cactuses, but in cultivation it is confined to Nopalea coccinellifera (Fig. B), which is now universally known as the cochineal cactus. The natural history of the cochineal insect is interesting. Both male and female are bright red in color, but the latter, from 150 to 200 times as numerous as the former, are alone used as a dye. In the Canary Islands these insects are reared in the winter, and from May to July the females are put upon the cactus plants. As soon as collected, in August or September, they are killed by hot water, steam, or by being placed in an oven, and then prepared for market. Since the introduction of aniline dyes the cochineal industry has suffered severely. In 1869, the amount exported from the Canary Islands, where by far the most is produced, was 6,310,600 pounds. In 1886, this had fallen to 1,449,968 pounds.

The price of the dye has also fallen from two shillings per pound in 1880, to one shilling in 1886.

The cactus family, cacteae, includes about 1,000 species, of which all but one are native to the western hemisphere. This one vagrant child is a species of rhipsalis or willow-cactus. Several cactuses of the genera opuntia and nopalea are naturalized in various parts of the world, however. A general view of the divisions of the family may be had from the following:

1. Melocactus. Link and Otto. ("Melon-cactus.") Species about 30, in Mexico, West Indies and south to Brazil and New Granada.

2. Mamillaria, Haworth ("teat-like"). Figs. E and F.

3 sub-genera;

1. Eumamillaria.

2. Coryphanta.

3. AnhaIonium.

Species about 300, occurring from New Mexico to Brazil and Bolivia.

3. Pelecyphora, Ehrenberg ("hatchet-bearing"). Fig. . Species 1, Mexican.

4. Leucktenbergia, Hooker (named for Prince Leuchtenberg). Fig. O. Species 1, Mexican.

5. Echinocactus, Link and Otto ("Hedge-hog cactus").

Figs. D, G, H. Including Malacocarpus, Gymno-calycium and Astrophytum.

Species about 200.

6. Discocactus, Pfeiffer ("disc-cactus") Species 2, in West Indies and Brazil.

7. Cereus, Haworth ("flexible"). Figs. A, Q, S, W, CC. Includes now Pilocereus, Echinopsis and Echinonyctanthus.

The genus is now divided into the following five subgenera :

1. Echinocereus.

2. Eucereus.

3. Lepidocereus.

4. Pihcereus.

5. Echinopsis.

The species are in the neighborhood of 200, growing from the southwestern United States and West Indies to the Galapagos islands.

8. Phyilocactus, Link (" leaf -cactus"). Fig. OO. Including Disocactus (not discocactus).

Species about a dozen, from tropical North America to Brazil.

9. Epiphyiium, Pleiffer ("upon a leaf"). Species 3, Brazilian.

10. Rhipsalis, Gaertner ("willow branch"). Figs. L and M.

It is divided as follows into sub-genera : 1. Eurhipsalis.

2. Lepismium.

3. Hariota.

4. Pfeiffera.

The last three names were formerly used for distinct genera. The species of rhipsalis number about 30, of which one is native to southern Africa, Mauritius and New Zealand. The remainder occur in tropical America.

11. Nopaiea, Salm-Dyck ("Nopal," Mexican name for cactus). Fig. B. Species 3, in Mexico, West Indies and South America. Nopalea coecinellifera is cultivated for the rearing of the cochineal insect. It is native to the West Indies.

12. Opuntia, Miller ("Opus," an ancient city). Figs. I, P, PP. R, T.

About 150 species are described. They inhabit North America from Canada to the tropics.

13. Pereskia, Miller (named for Nicholas F. Peiresk).