222 EXPERIMEiTT STATION RECORD. 



embryo. This was tested by making a study of the life duration of seeds at two 

 high temperatures, and using these values to express the relation between time 

 and temperature for the coagulation of protein formation to determine the life 

 duration at any desired temperature. 



Plant autographs and their revelations, J. C. Bose (Nature [London'], 93 

 U914), No. 2334, PP- 546-550, figs. 10; noted in Agr. News [Barbados], 13 

 (1914), No. 322, p. 279). — ^This is a condensed account of the author's recent 

 investigations (E. S. R., 30, p. 429). 



Results of 12 methods employed ai'e elaimed to agree in showing that the 

 nervous impulse in plants is fundamentally identical in character with that in 

 animals. Its velocity of transmission in plants tested was less than in those 

 of the higher, but greater than in those of the lower, animals, being affected 

 by conditions in both cases. 



The rate of plant growth and its variations under the action of food materials 

 and different forms of stimulation can be recorded very quickly, it is claimed, 

 by the crescograph, an instrument devised by the author, which offers a delicate 

 means of testing the effects of foods, stimuli, etc., in agricultural experi- 

 mentation. 



A comparison of the responses of sessile and motile plants and animals, 

 V. E. Shelford (Amer. Nat., 48 (1914), No. 575, pp. 641-674). — On account of 

 the increased attention the biologists are giving to responses to stimuli, the 

 author presents an analysis of the kinds or aspects of response, the kinds of 

 response that are comparable, and the bearing of response phenomena on 

 biological theory and controversy. 



The paper aims to show that the numerous kinds of resjionse are reducible 

 to a few simple types common to both plants and animals and that the failure 

 to consider all types has been responsible for confusion and various one-sided 

 theories. 



A bibliography is appended. 



Thermotropism of roots, Sophia Eckebson (Bot. Gaz., 58 (1914), No. 3, pp. 

 254-263, figs. 6). — ^An investigation of seedlings of Raphanus satirus and PUum 

 sativuin, whose roots were exposed to unilateral warming, and a study of 

 permeability of roots of these plants are said to show that thermotropic curva- 

 tures of roots and permeability of their cells to solutes both vary with species 

 and with temperatures employed. It is also stated that the greater permeability 

 is on the concave side of the root, changing with the thermotropic reaction, 

 these two showing an exact pa*'allel, and turgor change due to permeability 

 accounting for the curvature. Heat also acts here not as a stimulus, but by 

 affecting permeability as a direct factor producing curvature. The general 

 conclusion is reached that thermotropism is not a tropism but a turgor move- 

 ment. 



On the nutritive conditions determining the growth of certain fresh- 

 water and soil protista, H. G. Thornton and G. Smith (Proc. Roy. Sac. 

 [London], Ser. B, 88 (1914), No. B 601, pp. 151-165, pi. 1. figs. 2).— This is a 

 preliminary study of the determining causes of changes noted in the successive 

 but usually irregular developmental phases of certain organisms. 



A study of the cultures of soil flagellates is said to show that, as compared 

 with Euglena, they are able to live in cultures to which organic compounds of 

 varying natures have been added, this comparative impartiality being the 

 result of the holozoic mode of nutrition, and the development of the flagellates 

 being dependent on the bacterial growth. It is said also that the presence of 

 Miquel salts in the solution is necessary for the growth of the soil flagellates 

 and for the proper development of the different types of bacteria upon which 

 they feed. 



