All the larger-stemmed kinds may be kept in health when grown on their own roots; but for some of the smaller species it is a good plan to graft them upon the stem of some of the Cereuses, C. tortuosus or C. colubrinus being recommended for the smaller kinds, and for the larger C. peruvianus, C. gemmatus, or any one the stem of which is robust, and of the right dimensions to bear the species of Echinocactus intended to be grafted.  Some growers prefer to graft all the small Echinocactuses upon other kinds, find certainly, when properly grafted, they are safer thus treated than if grown on their own roots.  In grafting, the two stems (stock and scion) must be cut so that their edges meet, and in securing them two or three stakes must be placed in such a way as to afford support to the graft and hold it firmly in position.

Propagation.—­Besides grafting, cuttings of the stems may be utilised for the multiplication of Echinocactuses, first removing the upper portion of the stem and putting it into soil to root, and afterwards, as lateral stems develop on the old stock, they may be cut away with a sharp knife, and treated in a similar manner.  Should a plant become sickly, and look shrivelled and cankered at the base, it is always best to cut away the healthy part of the stem, and induce it to form fresh roots, thus giving it a new lease of life.  Seeds of these plants may be obtained from dealers, more especially Continental nurserymen, and to watch the gradual development of the plant from the seedling is both interesting and instructive.  The seeds should be sown in soil, and kept moist and warm; in about a month after sowing, the little pea-like, green balls will be seen pushing their way through the thin covering of soil, and gradually but slowly increasing in size, their spines also increasing in number and strength, the ridges forming according to the character of the species, till, finally, they assume the mature characters of the plant, both in stem and habit.  The flowers, of course, appear according to the length of time it takes for the species to grow to flowering size.

Species.

E. brevihamatus (short-hooked).—­Several kinds of Echinocactus are distinguished from the rest in having the ridges divided into tubercles, which are often globular and arranged in a spiral round the stem, as in the genus Mamillaria; to this section the present species belongs.  The stem is almost sphere-shaped, from 4 in. to 6 in. high, the tuberculated ridges about 1/4 in. deep, and upon each tubercle is a tuft of about a dozen brown, radiating spines, with a long central one hooked at the point.  The flowers are borne in clusters on the top of the stem, three or four opening together; they are 1 in. in length, and the same across the spreading petals, which are pink, shaded with deep rose.  A native of the mountainous regions of South Brazil; introduced about 1850.  Flowers in summer.  This pretty little plant will thrive if placed upon a shelf in a greenhouse where it will have full sunshine during the greater part of the day.  It grows very slowly, especially when on its own roots, but succeeds better when grafted on another kind.