But I should easily discover that some plants grew best in one soil, some in another, some with more moisture, some with less; whilst the very circumstances of soil, moisture, and so on, which were essential to some, might be enfeebling or destructive to others. No one will for a moment doubt that the kind of nutrition was of great importance in all, and this would necessarily lead me to infer that, "If I desired to get such a fungus, I must have more moisture, less air, less heat or light, or another soil," and so on. In a plant, you must also look to the roots and other parts of the organism. Now this is exactly what should be done in regard to tumours; and for no reason more cogent than that the great beauty and beneficent effects of Mr. Abernethy's views may become practically useful; for in the same manner that we would desire to influence the plant or the fungus through the sources whence it derives its nourishment, as air, water, various ingredients in the earth, and so on; so the only channels by which _we_ can effect any influence, are those organs by which these matters are ultimately changed into the structures we wish to maintain, or we desire to get rid of, as the case may be. Now, although the number and relations of these organs may render the investigation more difficult in one case than in another, as they become more multiplied, or as the animal or vegetable is more or less simple or complicated in structure; yet, whether we take our example from man, or any other animal—or, in fact, any organized being of the countless modifications we find in nature—the instrumentality through which the vital power acts is neither more nor less than the assimilating organs. If we have been too professional in this discussion, we plead, as an apology, that in no one point in the whole range of surgical practice would unnecessary suffering be avoided more frequently than on the subject before us; provided only that what is clear and positive, as distinguished from what is conventional and erroneous, were once popularly familiar; for, amongst other evils, most of the operations in this department of surgery are not only superfluous—to use no stronger term—but they practically _interfere more than any one thing whatever_ with the progress of the scientific investigation of the nature of these maladies. The removal of them by operation is too commonly undertaken, not only under circumstances which, as Abernethy said, "add cruelty to calamity," but for reasons which logically forbid such a proceeding; and although there are conditions which call for such interference, yet those under which it is usually instituted help only to obscure the real relations of the disease, and to throw the shadowy veil of an irrational empiricism over the operations of nature.