128 EXPEEIMENT STATION RECORD, 



pine which had been girdled at least five years previously by some rodent. It 

 had continued to live, growing above (not below) the decorticated portion, 

 but apparently only between the first and second whorl of branches, the first 

 of which was just above the injured region which had been denuded of bark, 

 cambium, and some of the outer sapwood. The circumstances are held to show 

 that mineral food must have passed from the roots to the leaves and that 

 material was practically prevented from passing down from the leaves to the 

 roots, but no complete explanation is yet evident for the nonincrease in size of 

 the portion between the second and the third whorl of branches. 



A second case is noted of a white pine, originally a forked tree, in which 

 natural grafting between the two forks has taken place in three or four places. 

 One stem has been separated below but continues to grow, the crown now being 

 more vigorous and thrifty than that of the rooted member. The taper of the 

 severed tree has been altered and is now considerably less than that of the 

 other. An important feature is the continued healthy growth of the severed 

 stem below the graft and the more rapid increase at the junction end of the 

 trunk than at the severed end. The upper end apparently permits only such 

 food as its needs do not require to pass downward to the lower portion of the 

 severed trunk, which has no roots, live limbs, or leaves. 



The influence of chlorids and nitrates of potassium and sodium on ger- 

 minating plants, H. MiciiEELS {Intermit. Ztschr. Phys. Chem. Biol., 1 {1914), 

 No. 5-G, pp. 412-419). — Studies were carried out regarding the effects on per- 

 centage of germination, length of first leaf, length of root, and weight of the 

 plantlet in case of wheat grown in (solutions of potassium chlorid, potassium 

 nitrate, sodium chlorid, and sodium nitrate, which show almost the same degree 

 of dissociation at the two concentrations employed (t-ott find roW normal). 



In solutions uninfluenced by the presence of an electrical current the chlorin 

 ion was more harnjful than the nitric acid ion and the sodium more so than 

 the pota.ssium ion. The nitric acid ion acts favorably on leaf length, plant 

 weight, and length of root hairs, but this is not true of the chlorin ion. While 

 sodium is more harmful than potassium, it gives greater root length. The 

 same general results were obtained during electrolysis of the solutions. The 

 diiTerences observed are ascribed to physiological properties of the same ions 

 and not to any chemical properties. 



A method of prophesying the life duration of seeds, W. Crocker and J. F. 

 Groves {Proc. Nat. Acad. Sci., 1 {1915), No. 3, pp. 152-155). — This article gives 

 a detailed account of investigations previously noted (E. S. R., 32, p. 221), in 

 which the authors claim that gradual loss of viability in seeds during storage 

 is due to a slow coagulation of the proteins in the plasma of the embryo. They 

 have found in experiments a rather close agreement between calculated and 

 found values, which indicate that a time-temperature formula for the coagula- 

 tion of proteins can be applied as a temperature-life duration formula for 

 seeds, at least under the conditions of these experiments. 



Light and the rate of growth in plants, D. T. MacDougal {Science, n. ser., 

 41 {1915), No. 1056, pp. 467-469) .—Attention is called to a statement by the 

 author (E. S. E., 15, p. 3.39) in which it was shown that light has no invariable 

 or universal relation to growth in plants. In the present paper additional 

 data are presented to substantiate this claim. The investigations of Richards 

 and Spoehr on the growth, hydratation, and acidity in certain species of 

 Opuntia (E. S. R., 30, pp. 429, 4.31) are said to have a bearing on this problem. 



The results of an extended series of observations on 0. dlakeana are given, 

 which are said to show that the growth of the enlarging joints is at a mini- 

 mum in the morning, with a rapid acceleration parallel with the rising tem- 

 perature of the open, reaching a maximum about noon and then decreasing to a 



