REVIEWS 793 



of the subject. It appears reasonably certain to the reviewer that the 

 slow growth in the trees studied during the early part of their existence 

 argues their origin in dense stands when the individual stems were in 

 keen competition for growing space. Later on, the stands becoming 

 open, the individual trees were making their maximum diameter growth 

 when approximately 100 years of age when they were cut. It is 

 reasonably certain were the trees studied growing in closed stands 

 when cut, rings width would not have shown a gradual increase by 

 periods of years during the entire time covered. In other words, 

 growth tendency is so subject to modification by various environ- 

 mental factors whose effect cannot be separately determined, it is an 

 extremely unsafe assumption to assign variations in average ring 

 width at different periods in a given tree's existence, to age. Although 

 the smoothed curve of the annual ring width expresses the growth 

 tendency of the oaks considered under their particular environment, 

 it would not likely express the same growth tendency were the oaks 

 under another environment. J. W. T. 



Growth of Oak in the Osarks. By Frederick Dunlap. University 

 of Missouri, Research Bulletin 41, pp. 28. Columbia, Mo., March, 1931. 



Although Professor Dunlap is credited with being the author of this 

 interesting bulletin — the swan song of the defunct Department of 

 Forestry at the University of Missouri — he is at pains to explain that 

 Professor Pegg is joint author. This work was originally his as 

 mdicated in the acknowledgment at the end. As written by him it 

 contained much explanatory matter designed to make the results more 

 readily understood by the layman. After Professor Pegg's resignation 

 the manuscript was returned with a request to reduce it and make it a 

 technical bulletin, and in doing so Professor Dunlap added his own 

 name. Proof as submitted never showed any author's name, as this 

 is added with title and cover page at the last minute. 



This bulletin deals with the rate of growth of the four principal 

 species of oak on certain poor soils in the Ozark region of Missouri. 

 The species are black oak, black jack oak, white oak, and post oak. 

 The study shows that the growth of post oak and of black jack oak is 

 too slow to warrant their retention in the managed forest. Black oak 

 grows more rapidly than white oak in the first century — at 100 years 

 of age the former averages 15 inches d. b. h., the latter 10 inches d. b. h. 



