Page:Popular Science Monthly Volume 84.djvu/568

564 I have already spoken of the sprouting capacity of the chestnut, and for various reasons have stated that when coppicing is too long continued it can only result harmfully. On the other hand, the sprout-producing ability per se should be reckoned as a distinct advantage to the species. We know that when the Lumberman fells such trees as the pine or hemlock he sounds the death knell of that individual. On the contrary, in the case of the chestnut, as we have seen, this is just the operation which leads the way to an increase in the number of individuals, for where one tree existed before, now four or five ultimately develop, sprouting from the stump. This kind of "vegetative" reproduction which, eventually, of course, results in increased seed production, is naturally an important factor in prolonging the life of the species. Zon says of the chestnut in southern Maryland:

There is, possibly, another point which may be in favor of the chestnut tree, although it applies only to the southern representatives of the species. As far as we can judge from reports and surveys, the progress of the chestnut bark disease into the southern states has been slow: at least, it has apparently spread into this territory with no such rapidity as has been remarked in the northern states.

Under the circumstances, it is entirely reasonable to assume that some condition exists in the south unfavorable to the development of the blight fungus. Various explanations have been offered, but none of them is more than a hypothesis, since, as far as I know, no accurate scientific investigation of the case has been made.

Perhaps the most plausible theory is to the effect that the southern chestnut may contain a larger amount of tannin than the northern tree and that this higher content of tannin may be inimical to a vigorous development of the fungus. Whether it is actually a fact, however, that a southern tree contains more tannin than a northern tree of equal age, has not been determined. We know that the tannic acid manufacturers use only southern chestnut for their material, and yet this may be simply because larger trees exist in the south, and we know that the older, larger trees contain more tannin. The actual comparative tannin content of northern and southern trees would form an interesting subject for future investigation. Dr. Clinton, acting on the supposition that some such relation as this might exist, has carried on some interesting experiments with the chestnut blight fungus in culture media containing various percentages of tannic acid. He has found, among other