Current Literature 529 



It will be noted that the heavier seeds germinate the more poorly. 

 From his 25 years' experience the author concludes that there 

 is no definite relationship between weight and rate of germinat- 

 ing capacity in seeds of the same species. The seed of P. nionti- 

 cola from Idaho, near the Canadian border, weighed in 1912, 

 15 grams, while the Californian seed of the same species in the 

 same year weighed 32 grams per 1,000. The seed weight of 

 P. jeffreyi, P. ponderosa, and P. scopulorum is 125, 46, and 

 30 grams respectively. The germination of the Rocky Mountain 

 form of the Douglas fir is always better than that of the Pacific 

 coast form. With the former the germination is far advanced 

 after 5 days and is often nearly finished after 10 days, while 

 with the latter germination is hardly commenced after 5 days 

 and is not completed until 30 or more days. The author regards 

 the two forms as distinct species. This is, of course, from the 

 standpoint of a commercial seedsman. 



C. D. H. 



Injury by Disinfectants to Seeds and Roots in Sandy Soils. 

 By C. Hartley. Bulletin 169, U. S. Department of Agriculture. 

 Contribution from the Bureau of Plant Industry. Washington, 

 D. C. 1915. Pp. 35. 



The experiments described in the above-named bulletin were 

 mostly performed in the forest nursery at Halsey, Nebraska ; 

 some of them, however, in the nursery of the Pennsylvania Rail- 

 road near Morrisville, Pennsylvania. Both soil and subsoil at 

 the former place were fine sand ; at the latter place, a light gray 

 sandy loam with a fine reddish sandy subsoil. Most of the bulle- 

 tin is concerned with discussions of the use of clear, commercial 

 sulphuric acid as a disinfectant, but others such as hydrochloric 

 and nitric acids, formalin, ammonia, lime-sulphur, mercuric 

 chlorid, copper acetate and zinc chlorid were employed in the 

 experiments. The greater part of the disinfectants was applied 

 in aqueous solutions, usually at the rate of two or three pints of 

 water for each square foot of seed bed. The treatments were 

 made chiefly upon Jack pine seedlings and seed beds, although 

 those of Western Yellow pine. Red pine and Pinus laricio were 

 also treated. 



