In all these industries, whether the fiber cultivated is flax, ramie, or jute, the machine question enters so largely into the problem of their successful establishment that the business must be conducted on a large scale. Even in the growth of Sisal hemp in Florida, should it be attempted, the enterprise will only pay when the necessary mill plant for extracting the fiber is able to draw upon a cultivated area of five hundred acres. In other words, the small farmer can never become a fiber producer independently, but must represent a single wheel in the combination. [Illustration: THE LUFFA, OR SPONGE CUCUMBER.] The subject is a vast one, and, while I have been able to set forth the importance of these industries as new sources of national prosperity, only an outline has been given of the difficulties which are factors in the industrial problem. Summing up the points of vantage, the market is already assured; through years of study and experiment we are beginning to better understand the particular conditions that influence success or failure in this country; we have the best agricultural implements in the world, and American inventive genius will be able, doubtless, in time, to perfect the new mechanical devices which are so essential to economical production; our farmers are intelligent and industrious, and need only the promise of a fair return for their labor to enter heart and soul into this work. WHAT IS SOCIAL EVOLUTION? BY HERBERT SPENCER. Though to Mr. Mallock the matter will doubtless seem otherwise, to most it will seem that he is not prudent in returning to the question he has raised; since the result must be to show again how unwarranted is the interpretation he has given of my views. Let me dispose of the personal question before passing to the impersonal one. He says that I, declining to take any notice of those other passages which he has quoted from me, treat his criticism as though it were "founded exclusively on the particular passage which" I deal with, "or at all events to rest on that passage as its principal foundation and justification."[4] It would be a sufficient reply that in a letter to a newspaper numerous extracts are inadmissible; but there is the further reply that I had his own warrant for regarding the passage in question as conclusively showing the truth of his representations. He writes:-- Should any doubt as to the matter still remain in the reader's mind, it will be dispelled by the quotation of one further passage. "_A true social aggregate_," he says ["_as distinct from a mere large family_], _is a union of like individuals, independent of one another in parentage, and approximately equal in capacities_."[5]