442 EXPERIMENT STATION RECORD. 



many weak and slow growing branches. The former produce the greater 

 fi mount of timber. The progeny of the broad-crowned seed trees are more 

 vigorous than those of the small-crowned seed trees. In general the habits of 

 the progeny more or less resemble those of the seed parent. 



The progeny of very old seed trees are essentially smaller than those of very 

 ypung seed trees. On the other hand, there appears to be no great variation 

 among progeny from seed trees ranging in age from 15 to 100 years. 



The progeny of different seed trees showed a varying degree of resistance 

 against needle blight. In one stand the progeny from a dominant seed tree 

 were apparently immune to blight, whereas the progeny of a suppresse<l seed 

 tree in the same stand showed a strong disposition to blight. In one case 

 practically all the offspring of the parent were attacked by blight, except a few 

 individuals which appeared to be Immune. 



Experiments on individual selection with forest trees. — II, Pinus austriaca, 

 E. Zedeebauee iCentbl. Gesam. Forstw., 39 {1913), No. 5, pp. 197-204, figs. S).— 

 A study of inherited tendencies in the progeny of Austrian pine seed trees is 

 here reported in detail. The author's conclusions are essentially the same 

 as those reported in the above noted experiment with Scotch pine. 



On the biolog'y of Siberian pine (Pinus sibirica), R. Pole {Izv. Imp. St. 

 Peterh. Bot. Sada (Bui. Jard. Imp. Bot. St. Peterst).), 13 (1913), No. 1-2, pp. 

 1-22, pis. 3, figs. 3). — A study of the Siberian pine with reference to its distri- 

 bution, habitat, reproduction, and economic importance. 



The periodic phenomena of pine reproduction on the polar forest border. 

 A. Renvall {Fcnnia: Bui. Soc. Geogr. Finlande, 29 {1912), No. J,, pp. XII+15Ii, 

 pi. 1). — This embraces the results of a study by statistical methods of pine 

 reproduction in the north polar region. Consideration is given to the phe- 

 nomena of flower development, cone formation, and seed production. A bibli- 

 ography of cited literature is appended. 



The streng'th of long-seasoned Douglas fir and redwood, A. C. Alvarez 

 {Univ. Cal. Pubs., Engin., 1 {1913), No. 2, pp. 11-20, pis. 2).— This bulletin 

 report^ mechanical tests of Douglas fir and redwood timber which had been 

 used as wall studding, floor joists, and underpinning in a building on the Uni- 

 versity of California campus for a period of 37 years. 



Although the number of tests was not large enough to .lustify any sweeping 

 conclusions, a comparison of averages from the results with those given by 

 Cline and Heim (E. S. R., 2S, p. 50) on similar timber air-seasoned for 2 

 years shows that the long-seasoned timber possessed greater strength in longi- 

 tudinal shear, as well as a higher modulus of elasticity and higher fiber stresses 

 at the elastic limit and at the maximum load. The maximum crushing strength 

 in compression longitudinally is 40 per cent higher for the long-seasoned Doug- 

 las fir, but its elastic limit is 30 per cent lower. The longitudinal crushing 

 strength of the long-seasoned redwood is 25 per cent greater. The well-pre- 

 served condition of the floor joists shows that proper ventilation will prevent 

 the decay of timber that is exposed to a damp atmosphere. 



Further mechanical tests of a similar nature are to be made in the near 

 future. 



Volume table for redwood, compiled by A. W. Elam {Alameda, Cal., 1913, 

 pp. 20). — This volume table is designed for scaling 16 ft. logs, 18 to 144 in. in 

 diameter and with a taper of from 2 to 8 in. 



The physiological atavism of our oaks and beeches, W. Magnus {Biol. 

 Centhl, 33 {1913), No. 6, pp. 309-337).— This comprises a review of our knowl- 

 edge relative to growth periodicity among woody plants of various climates, 

 with special reference to the tendency of oaks and beeches to retain the last 

 years' foliage until growth starts in the spring. The author concludes that 



