CONCENTRIC RINGS OF TREES. 261 



spruce from Puget's Sound, of known age, or nearly fifteen years old. 

 The section was twelve inches in length, and on one end had eighteen 

 rings and on the other end had only twelve. Commissioner Loring 

 expresses the opinion that " this settled the question, that rings at all 

 times could not be relied upon as an index of the age of trees." 



Hon. J. T. Allan, of Omaha, superintendent of tree-planting for 

 the Union Pacific Railroad Company, in a recent letter says : " Any 

 intelligent man, who has given any attention to this matter of yearly 

 tree-growth, knows that the rings are no index of a tree's age. H. P. 

 Child, superintendent of ' the Kansas City stock-yards, shows me a 

 section of pine eight years old, with nineteen rings, and a soft maple 

 of nearly fourteen years, with sixteen very distinct rings, in addition 

 to which there are forty-seven less distinct sub-rings." 



In conclusion, that the more distinct concentric rings of a tree ap- 

 proximate, 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 conspicu- 

 ous, yet often more distinct than the annual rings, exist, is equally cer- 

 tain : 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 sud- 

 den and more or less frequent changes of weather and requisite condi- 

 tions 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 cause, the condensation produces 

 a more pronounced and distinct ring than the annual one. Query : 

 Has a tree grown in a conservatory, or place of unchanged conditions 

 of heat and moisture, any concentric rings ? 



