The time honored method of determining the age of trees by counting their concentric rings has received some very hard blows from recent observations made on the growth of trees. An article in the _Popular Science Monthly_, from the pen of A. L. Childs, M.D., gives some facts which show that these rings do not indicate the age of the tree, and shows what they do indicate. The following passages from the article will give the ground on which his deductions are based: “In June of 1871 I planted a quantity of seed as it ripened and fell from some red maple trees. In 1873 I transplanted some of the trees from these seeds, placing them on my city lots in Plattsmouth, Nebraska. In August, 1882, finding them too much crowded, I cut some out, and, the concentric rings being very distinct, I counted them. From the day of planting the seed to the day of cutting the trees was two months over eleven years. On one, more distinctly marked (although there was but little difference between them), I counted on one side of the heart forty rings. Other sides were not so distinct; but in no part were there fewer than thirty-five. * * * * Hence, from my own record, I _knew_ the tree had but twelve years of growth; and yet, as counted by myself and many others, it had forty clear concentric rings. * * * Hon. R. W. Furness, late Governor of Nebraska, so well known as a practical forester, has kindly furnished me with several sections of trees of known age, from which I select the following: A pig-hickory eleven years old, with sixteen distinct rings; a green ash eight years old, with eleven very plain rings; a Kentucky coffee-tree ten years old, with fourteen very distinct rings, and, in addition to these, twenty-one sub-rings; a burr-oak ten years old, with twenty-four equally distinct rings; a black walnut five years old, with twelve rings. * * * In conclusion, that the more distinct concentric rings of a tree approximate, or in some cases exactly agree, in number with the years of the tree, no one, I presume, will deny; but that in most, and probably nearly all trees, intermediate rings or sub-rings, generally less conspicuous, yet often more distinct than the annual rings, exist is equally certain; and I think the foregoing evidence is sufficient to induce those who prefer truth to error to examine the facts of the case. These sub-rings or additional rings are easily accounted for by sudden and more or less frequent changes of weather, and requisite conditions of growth—each check tending to solidify the newly-deposited cambium, or forming layer; and, as long intervals occur of extreme drought or cold, or other unfavorable causes, the condensation produces a more pronounced and distinct ring than the annual one.” C. L. S. C. WORK. By Rev. J. H. VINCENT, D.D., SUPERINTENDENT OF INSTRUCTION.