112 EXPEKIMENT STATION RECORD. 



The development of the primary and secondary conductive tissue and 

 lignification of cell walls was the same as for the roots. The central 

 C3'linder of the stem increased most rapidly under blue light and least 

 under green, with red as intermediate. The periderm of the stem 

 was least developed under green light, most under blue, and red inter- 

 mediate. 



The influence of changes of temperature on the respiration of 

 plants, W. Palladin {Rev. Gen. Bot., 11 {1899), No. 127, pp. 21^1- 

 257). — The extremities of etiolated seedlings of Viciafaha with a few 

 leaves were cut off and placed in vessels containing a 10 per cent solu- 

 tion of saccharose. One lot Avas kept in the laboratory at an average 

 temperature ranging from 17 to 20^ C. A second lot was placed in a 

 vestibule where a lower temperature, 7 to 12° C, was experienced, 

 and the third lot was placed in a thermostat in which a temperature of 

 from 36 to 37.5° C. was maintained. After from 3 to 7 days in these 

 temperatures equal lots were brought together and kept at a medium 

 temperature of from 18 to 22°, and the amount of carbon dioxid liber- 

 ated per gram of plants was ascertained. 



It was found that the plants which had lieen kept in the medium 

 temperature gave off 55.8 mg. per gram; those removed from the 

 low temperature to the medium gave off 78.1 mg. ; and those from 

 the highest to the medium temperature, 85.4 mg. per gram of plant 

 weight. The change from a lower to a higher or a higher to a lower 

 temperature resulted in an increased respiration. The cause for this 

 phenomenon was not ascertained. 



On the influence of anaesthetics on the respiration of plants, 

 N. MoRKOWiNE {Rev. Gen. Bot, 11 {1899), JVoh. 128, pyp- ^89-303; 

 129, p>p. 3Jf.l-352). — The author experimented with the etiolated leaves 

 and leaf buds of Vicia faha and Lupj'inus luteus and the green leaves 

 of Ficus elastica and Phylodendroii sp. ; also upon the embryos of 

 sprouted wheat. As anesthetics, alcohol, ether, hydrochlorate of 

 morphine, and hydrochlorate of solanin were used. The plants were 

 placed in a Pettenkofer apparatus and the I'espiration determined. 

 The experiments are described in detail. 



Contrary to the conclusions of Bonnier and jNIangin,' the author 

 found that if the exposure to anaesthetics be prolonged for quite a 

 number of hours, or even for several davs, the intensity of respira- 

 tion was considerably increased. Under the influence of alcohol, the 

 intensity of the respiration of etiolated plants was increased 1^ times. 

 With ether, the respiration of etiolated leaves of Vicia faha was 

 more than doubled. It Avas found that the hj^drochlorate of morphine, 

 1:2,000, did not in any way affect the respiration of plants. When, 

 however, the quantity or morphine was 1:500, the respiration of the 

 plants was increased \\ times. 



lAnn. Sci. Nat. Bot., 7. ser., 1886, p. 5. 



