Periodical Literature 329 



as 29. The earthworm also, but not necessarily, feeds on dead 

 vegetable matter, but never on live plants. As regards the com- 

 minuting of the soil, the significance of the earthworm has been 

 overestimated ; in this respect, the edaphon has much more signifi- 

 cance, and forms an intervening link between the mechanical 

 action of the earthworm and the chemical of the soil bacteria. 



Untersuchungen iiber die Erndhrung des Regenwurms. Forstwissenschaft- 

 liches Centralblatt, November, 1915, pp. 523-4. 



SILVICULTURE, PROTECTION AND EXTENSION 



Upon the basis of 20 tree sections (fir 



Interlucation and beech), several of which are pictured, 



and Forstmeister Roth, of the Hungarian Ex- 



Increment periment Station, discusses the influence of 



severest thinning (Lichtung, for which we 



propose the new term interlucation) on increment. 



The response to sudden access of light, as is well known, is, as 

 a rule, not immediate, at least not in height growth : an adaptation 

 of the foliage to the new light conditions is first necessary ; indeed, 

 a retardation of growth is usually noticed. As regards diameter, 

 the response appears in the width of the annual ring almost sud- 

 den. On a section of fir which for 105 years showed hardly .7 mm 

 average width of ring, the first ring after interlucation showed 

 no influence, the following rings showed a width of 2 to 4, 5, 8, 

 10, 10 mm; in 5 years an increment ten times as large as in the 

 preceding periods. 



Another section of 134 years age, for 55 years made hardly .4 

 mm rings, then for 8 to 10 years in opener position made up to 

 2 mm width, then for another 55 years under suppression the 

 width fell to .6 mm on the average, altogether in 126 years the 

 diameter was only 135 mm ; then suddenly set free, the first ring 

 showed no influence, but the next year's ring was 2 mm, and then 

 followed rings of 4, 7, 7, 7, 8.5, 7, 7 mm, in other words, the 

 light produced 14 times greater increment. 



A third section, at 84 years old, showed only an average of 

 .7 mm ; after interlucation no response for first year, then 2, 4, 6, 

 6.5, 7.5, 8, 8, 6 mm, or ten times the former increment. 



