Now for evidence of the decline of this once famous apple. In Martyn's edition of Miller it is said, "the Red-streak so much celebrated by writers of the last century, appears almost to have survived its fame as a cider apple." Mr. Knight in his Pomona Herefordiensis observes, "trees of the Red-streak can now no longer be propagated, and the fruit, like the trees, is affected by the debilitated eld age of the variety, and has in a very considerable degree, survived those qualities to which was owing its former fame; the cider which has been made of it alone, within the last thirty years having rarely proved good." Here then we have most satisfactory proofs of a once famous apple; handsome, hardy, productive, and affording cider or surpassing excellence; having become feeble, diseased and almost if not quite extinct. Such then, when they come to be examined, are the facts and arguments advanced by Dr. Lindley in support of his assertion that "there is not only no proof of the correctness of Mr. Knight's theory, but the strongest presumption to the contrary."

As in the case of the natural death of forest trees, the facts are too numerous and too well authenticated, proving that valuable varieties of plants propagated by extension, have ultimately become diseased and unproductive, and consequently extinct.

Dr. Lindlet thus explains these facts - "a tree is allowed from some cause or other to become unhealthy, a piece cut from it and put upon another tree, carries its disease with it; when again divided, the disease is again propagated; and this will go on so long as the unhealthy plants remain exposed to the circumstances which originally caused their bad health."

Adverse circumstances certainly tend to make plants unhealthy, and a variety of apple which has been in existence two hundred years is likely to have been exposed to a greater amount of damaging influences than a variety which has been in existence only fifty years; therefore we may reasonably conclude that the old variety, owing to the effect of these adverse external influences alone, will be less healthy than the younger variety.

Dr. Lindley may tell us that disease does not arise from internal but external circumstances. But the question will intrude, how are we to avoid these circumstances? what is "the some cause or other" which makes them unhealthy? If the plants of a variety in a certain locality only become diseased, then we might have some grounds for hope, but when we remember that of the apples mentioned by Parkinson, the names only remain, and when we now know that old varieties of the apple and pear decline in vigor and productiveness, first in cold wet ungenial soils; lastly in warm dry situations, how are we to prevent this? "Change the circumstances; keep off the cause of the evil and the evil will gradually disappear as in the case of the Golden Pippin." Are we then to establish a plant hospital in the South of France or in Madeira; what other means are we to resort to, seeing that the Golden Pippin is the only instance mentioned of trees of an almost worn oat variety existing in a comparative state of health.

The duration of both animal and vegetable life depends upon the original vigor of the constitution as well as adventitious circumstances. There are inherent as well as external influences with which we have to contend. Thus of human beings; many die in infancy, others may live a century. Of ten thousand born, hardly one may die through exhaustion of vitality, or sheer old age. - I mean, without the exhibition of any active disease. Again, of two children born with equally vigorous constitutions; one whose constitution has been subject to many trials may die in forty years, whilst the other more favorably circumstanced may live double that time. In like manner individual seedling plants differ greatly in constitutional vigor. Some we find are so weak that the first adverse influence to which they may be exposed destroys them, whilst other plants of the like kind and age, growing under the same circumstances, remain unharmed. Why is this? Because of the difference in constitutional vigor. Some external influence may have been the immediate cause of death, but the inherent feebleness of the plant was the predisposing cause which led to its destruction.

So of plants with originally vigorous constitutions; few may die simply of exhaustion of vitality, and a tree in the prime of its existence may being sound at heart, if I may so speak, will, owing to their inherent strength be restored to better health, exactly as in the case of animals in the prime of life laboring under local or transitory circumstances affecting their health. But we may graft a scion of an old nearly worn out variety on a healthy young stock, we may plant it in a situation where trees of the same variety continued, previously, in health and vigor upwards of a hundred years and where younger varieties now grow healthy and vigorously, but "the young stock," as Mr. Knight observed, "can give nutriment only, not new life;" it is found therefore, that the feeble scion, like a weak seedling, soon shows symptoms of disease. If it be objected that external influences first caused the feebleness, this may be said as reasonably of the infirmities of age in animals. It is inherent weakness in both which renders the attack of ordinary external influences formidable.

When a variety of apple or potato has arrived at the best and most productive period of its existence, is it rational to suppose or expect that the ingenuity of man can keep it stationary forever, and prevent its decline? The inherent, and many of the external influences which lead to debility and death, are beyond the control of man; and every adverse influence to which plants or animals are exposed, contributes more or less, to prostrate and wear out the constitution; and the power of external influences increases in proportion to the diminution of vital power. Man, by various expedients, may postpone the evil day, but he cannot prevent its coming. He may, for instance, betake himself to Italy or Madeira, in order to bolster up his feeble constitution, and he may take plants of his favorite old invalid fruit trees, with him, as a warmer climate is found to be as beneficial to them as to him, and both may return to their native land considerably fortified, but certainly not restored to the vigor of youth.