A Brazilian newspaper has some curious information about the plague of rats, which may well reconcile us to our smaller annoyances from these prolific vermin. They have destroyed almost the whole products of agriculture the past year. The bamboo everywhere abounds in the Brazilian forests. The popular explanation is that every cane of bamboo, sprouts with a grub, and that when the bamboo ripens and dies, the germ becomes a fully developed rat. But the curious and rational explanation is that the bamboo arrives at maturity, flowers and seeds at intervals of several years, varying with different species. Each cane bears about a peck of edible seeds, resembling rice, very fat and nourishing, and the quantity is enormous. The process of decay is hastened by the borings of the larva, and they, thinks the Brazilian, give rise to the grub developing into a rat; the increase in the rodents is very great. The crop over, the rats begin to emigrate for want of food, invading the plantations and houses, and consuming everything edible. If this happens at the time of corn planting, the seed is consumed as fast as it can be put into the ground, often six times.

The mandioca and rice is all stolen, as is everything in the houses in the way of provisions and leather, if not carefully guarded in tin trunks. We suffer badly enough and often ask why care is not more frequently taken to exterminate the pests. It is said to be easily done, if you know how.

The Cochineal Insect affords large profits to the Mexicans, etc. Who knows but that the cost of covered glass houses would not be paid by our adaptive citizens? But we can command a surer industry in silk culture; the teaching done at our Permanent Exhibition we expect, will be followed up, till very many of our boys and girls find pleasing and profitable employment.

Let every gardener, and indeed everybody, inscribe somewhere on his premises where it can be daily perused, the words of the immortal Gibbon, in the 12th volume of his History of Rome; " In the productions of the mind, as in those of the soil, the gifts of nature are excelled by industry and skill. * * A single manuscript imported from Greece, is revived in ten thousand copies, and each copy is fairer than the original".

The literature of gardening, strictly so-called, is more extensive, pleasing, and informing than is generally supposed. First among American books should be placed Darlington's Life of Bartram, which has fascinations for the lover of nature, and of honest, natural men not at all inferior, though in a different way, to Boswell's Johnson. There is a vein of beautiful simplicity, with sometimes a touch of humor in the correspondence with his European friends. The finding of a new plant, or new turtle, is related with great accuracy and beauty, and Bartram's pursuits are extended beyond his gardening occupations. "Come over," he says to his neighbor Wilson, the ornithologist, "I have caught Napoleon," meaning a great eagle. Lord Petre, and his pear tree is a delightful episode. Dil-lenius and Collinson, with others of eminence, admired our American, and never tired of his letters and his seeds. Every lover of nature should read this work. Then, Loudon's many volumes are treatises of information and pleasant reading. So industrious was he, (his wife tells the story), that having lost the use of his right arm by a quack shampooer, it was decided to cut it off.

The surgeons found him engaged on his great Encyclopaedia of Plants. Moving without agitation to the operating chair, he submitted without a cry, and when released tried to be allowed at once to return to his work. These notes will still further call attention to the best literature of gardening, forestry, and botany. The world owes much to Loudon and Bartram.

Mr. Henderson writes justly enough from his point of view; but let some one ask him from whence, if not from the air, do plants elaborate their special and wonderfully different characteristics, such as the various spices. Plant onion and hyacinth bulbs in contact and they will come true from the same soil. Again, bot-tanists tell us that sap and leaves contain minute particles of iron, whence do they obtain this mineral?