the small quantity of roots, compared with the size of the plant. 
It is now growing in a round tub, half filled with drainage- 
material, the plant resting on a foundation of bricks raised in 
the middle of the tub, to prevent its sinking on account of its 
great weight. ‘The upper portion of the tub is filled with soil, 
consisting of a mixture of loam and lime-rubbish nodules, firmly 
pressed round the base of the plant. It is kept in the Cactus- 
house, which, in order to suit tropical species, is maintained at a 
higher temperature in winter than is absolutely necessary for 
this and other Mexican species ;—we have already remarked, at 
Tab. 4486, that if Mexican Cactee could be cultivated in a house 
by themselves, they would require very little artificial heat. This 
plant has been nearly six years under our care: although it is 
apparently in a healthy state, and seems to grow, and though 
it has flowered, its increase is so small that we cannot determine 
the amount by simple measurement. From the tardy increase of 
what we believe to be young plants of this species (which, al- 
though now six years old from seed, are not yet more than two 
inches high and weigh barely two ounces), we infer that this 
species of Hchinocactus, to arrive even at the size of what m 
be called the small specimen figured (as compared with another), 
and to assimilate the vast quantity of solid granular matter 
which it contains, must require a period of time amounting to 
many centuries. J. S. : 
Fig. 1. Entire plant, very much diminished. 
