Page:An introduction to physiological and systematical botany (1st edition).djvu/370

 340 French islands. Such were the supineness and ignorance of the Spaniards, that he succeeded in conveying, not only the living insects, but the bulky plant necessary for their sustenance, notwithstanding severe edicts to the contrary. He had attended previously to the management of the Nopal, and made his remarks on the diseases to which it is liable. Of these the Gangrene is extremely frequent in the true Nopal of Mexico, beginning by a black spot, which spreads till the whole leaf or branch rots off, or the shrub dies. But the same kind of plant is often affected with a much more serious disease, called by Thiery "la dissolution." This seems to be a sudden decay of the vital principle, like that produced in animals by lightning or strong electricity. In an hour's time, from some unknown cause, a joint, a whole branch, or sometimes an entire plant of the Nopal, changes from apparent health to a state of putrefaction or dissolution. One minute its surface is verdant and shining; the next it turns yellow, and all its brilliancy is gone. On cutting into its substance, the inside is found to have lost all cohesion, being quite