Periodical Literature 515 



Reference is made to Prof. Klebs' observations in the tropics 

 (see F. Q., vol. XIV, p. 83), and to measurements by Engler on 

 four specimens of spruce through one season ; also to the volimie of 

 forest-phaenological observations edited by Wimmenauer, 1897, 

 and a few findings resulting from these observations are cited. 



The author's investigations were to prove that age, elevation and 

 soil differences in one and the same revier determine variations in 

 the height growth of young spruce in the same year, and that tem- 

 perature and hiimidity are determinative to a large degree. 



The measurements were made in seven stands at 250 to 500 m 

 elevation, on 25 to 50 spruces in each, from 4 up to 15 years old; 

 each specimen being nimibered and a graduated rule being attached 

 to it, so that every few days the growth of the leader could be read 

 off. -From 1 to 3 parallel series were made in each stand. In two 

 of the stands, maximum and minimum thermometers and hygrom- 

 eters were suitably placed. Other temperature and barometer 

 readings were also made and measurements of the previous per- 

 formances of the trees under observation. 



The measurements were platted in curves with time (days) and 

 lengths (mm) as co-ordinates. These curves permit close study 

 of behavior. 



Without going into the details, we may record some of the more 

 interesting findings. In a special series, it was shown that at first 

 the basis of the shoot lengthens most prominently, but gradually 

 the region of greatest increment progresses toward the tip. This 

 can be also observed by the density of the needles which first are 

 closely and evenly packed around the shoot, then show greater 

 intervals at the base and further show the region of greatest growth. 

 Also, the length of the needles show the same progress. In one 

 series, the most rapid growth took place from May 30 to June 4 

 (curves steep), then a falling off interrupted by two rapid periods. 

 This periodicity repeats itself in all series. No spruce, however, 

 takes a rest of several days, the progress is uniform, day and night 

 mostly alike. By middle July the growth is ended, only few con- 

 tinue 10 days longer. The early sprouters continue ahead all 

 stimmer and the late lag behind all the time. 



In the 4-year-old spruces, however, different from the 8 to 

 12-year-old, the height growth closes earlier. By Jime 7 half the 

 specimens ceased growing; eleven, however, after a period of rest, 

 between June 18 and 25, made a small addition. From the curves, 



