76 Forestry Quarterly. 



to work is reached, and the square washers in touch with the tree 

 will be overgrown in the well known manner. A series of pic- 

 tures of longitudinal cuts through the tested zone of the trees 

 exhibits the result of the pressure. 



It is interesting to note that in all species observed the growth, 

 i. e., the pressure, progressed evenly until the middle of Sep- 

 tember, then ceased quickly. In this connection, we recall the 

 interesting observations of Professor Buckout recorded in the 

 Quarterly, vol. V, p. 259, which seemed to make an exception 

 for the European Larch as compared with the White Pine. The 

 observations of Larch by Friedrich through three seasons show, 

 at least for two seasons, a falling off of growth energy in July, 

 as found by Prof. Buckout, authough this fact is not noted by 

 the investigator. The White Pine, observed through one season, 

 continued active at nearly constant rate, a Japanese Larch at an 

 increasing rate, until the end of September. 



The highest growth energy was noted for Basswood, which 

 showed still cell division and growth under a pressure of 36 at- 

 mospheres, while a horse-chestnut showed a limit of 10, Larch 

 of 12, and two maples ceased to grow under pressure of about 25 

 atmospheres. 



To give an idea of the progress of the pressures through the 

 season, and in different seasons, we condense some of the ob- 

 served data, through the years 1904, 1905, 1906, in the following 

 tabulation, the reading referring to the same date in the months, 

 namely the 5th. 



It would appear from these and other records that generally 

 speaking diameter growth in conifers is slower than in broadleaf 

 trees which coincides with general experience. 



Ueber die Dickenwachstumsenergie einiger Waldb'dume. Centralblatt 

 f. d. g. Forstwesen, 1908, pp. 482-498. 



