433 JOURNAL OF FORESTRY 



IV. Division of Experimentation in Natural Reproduction in 

 Norrland. 

 The activities of each division during the year 191 7 and also for the 

 triennial period 1915-1917 are outlined. The following articles are 

 printed in full : 



Edward Wibeck : Widens kulturplog. 



Experiments with a plow designed for cultivation and seeding in the 

 forest. Summary in German. Pp. 17-42. 

 Gosta Mellstrom : Skogstradens frosJittning ar 1917. 



A survey of the seed crop of different species in Sweden, together with 

 a discussion of climatic conditions affecting seed development. Such a 

 report is prepared annually. Pp. 43-68. Summary in German. 

 Ivar Tragardh : Skoginsekternas skadegorelse under ar 1916. 



A survey of insect damage during the year 1916, based mainly upon 

 reports by field officers. The article also contains technical descriptions 

 of the work of several of the important forest insects. Pp. 69-116. 

 Nils Sylven : 1917 ars knackesjuka i norra Vastergotland. 



A pine disease which has done great damage to forest plantations in 

 northern Vastergotland. Pp. 192-204. Summary in German. 

 L. Mattson : Stormharjningen i norra Dalarna hosten 1917. 



An account of damage by a tornado in northern Dalarna in the fall of 

 1917. Pp. 205-220. Summary in German. 

 Ivar Tragardh: Tallbocken (Monochamus sutor L.). 



A technical account of the activities of a pine borer which damages both 

 living and dead trees. Pp. 221-232. Summary in German. 

 Sven Petrini : Formpunktsmetoden och dess anvadning for formklassbestamning 

 och kubering. 

 A method of obtaining the form class and volume of single trees by the 

 use of the form point, based upon spruce material. Pp. 233-274. Summary 

 in English. 



An outline of the program for the period 19 18- 1920, inclusive, which 

 is summarized in English as well as German, is here reprinted. 



I. THE PROBLEM OF FOREST REGENERATION 



(a) Seed Investigations. Pine and spruce seed from different parts 

 of Norrland shall be investigated yearly so far as the supply of cones 

 will admit (F^). The investigation shall begin in a seed year suitable 

 for the determination of the best time for gathering cones (S) and 

 for the storage of forest seed (S and F). The biology of germination 

 shall be studied in the case of the most important forest trees, with 

 especial attention to the conditions of germination offered by the soil 



' The letters in the text have the following meaning : S, indicates the Forest 

 section; N, the Physical section; E, the Entomological section, and F, the 

 section for regeneration experiments in Norrland. 



