PERIODICAL LITERATURE 441 



much as 300 miles from the volcano ; that death-dealing blasts from 

 the volcano killed trees 25 miles away, destroying the forest over an 

 area of more than 1,500 square miles; that ashfall, so heavy as to ob- 

 literate all herbaceous plants except on steep hillsides, etc., covered an 

 area of about 970 square miles ; that mud flows so hot as to reduce 

 to charcoal all vegetation with which they came in contact were poured 

 out over an area of about 53 square miles ; that an area of about 39 

 square miles, in which there is no trace of former vegetation, was 

 probably swept by fires of great intensity, making the total area in 

 which all life was annihilated 140 square miles. 



The investigation into the exact causes of the character of the 

 destruction in the different zones of destruction remained rather in- 

 conclusive, whether in a given zone ashes or heat or acid, rain or hot 

 blast or heated mud flow was to be held responsible could not with 

 certainty be determined. The investigation reported was made three 

 years after the eruption. The herbaceous vegetation was found to be 

 partially restored on areas covered with ash to the depth of not more 

 than one foot. Certain grasses and the scouring rush in great luxu- 

 riance have overrun large areas. A river in flood in 191 5 washed away 

 a mantle of ash from three to six feet deep and many plants which 

 had lain dormant for three years resumed their vegetative activities. 

 Explanations of the cause of this dormancy are again inconclusive. 

 The trees suffered much more than the herbaceous vegetation, since 

 they were not protected by the ash covering. In order of injury the 

 author lists alder, birch, balsam, poplar, and willows. The latter have 

 the advantage in putting forth adventitious roots in abundance in the 

 new soil and go on with little apparent indication of disturbance. The 

 alder was completely exterminated and the birch nearly so. Dormant 

 buds protected by heavy bark from poisonous or scorching blasts have 

 carried on the life of many poplar trees for three years, but it is ap- 

 parent from the illustrations of the text that most of them will finally 

 succumb. 

 The Ohio Journal of Science, January, 1919, pp. 173-209. 



SILVICULTURE. PROTECTION, AND EXTENSION 



As a result of planting experiments instituted 



Forcstation in in November, 1909. with i -year-old seedlings, L. 



Central France Chancerel concludes that Q. paliistris, Q. rubra, 



O. phcUos. Betula nigra, Alnus cordifolia, Populus 



balsamifcra, and P. nigra (var. angnlata robiista for single trees) in 



