864 EXPERIMENT STATION RECORD. 



The <»,xperiments sliow that an increase of moisture always produced 

 a corresponding" increase in the carbon dioxid exhaled. An increase in 

 moisture was invariably followed during the first day or two by a slight 

 reduction in the carbon dioxid exhaled, but the grain soon recovered 

 and the increased quantity due to increased moisture asserted itself. 

 In one experiment where the amount of moisture was increased 8.88 

 per cent the quantity of catbon dioxid exhaled was more than doubled. 



The dry weight of the embryos at the end of the germinative period, 

 as shown by the tables, was more than doubled when the amount of mois- 

 ture was increased by soaking the seed 96 hours as compared with 24. 

 For the larger amount of moisture the embryo increases more in weight 

 for the same amount of carbon dioxid exhaled than it did when less 

 moisture was present. The ratio between these factors was found by 

 dividing the dry weight of the embryo by the weight of the carbon dioxid 

 exhaled. It was found that the ratio increased as the quantity of moisture 

 increased. In general the amount of moisture found in the embryo at 

 the end of the germinative period was about double that of the endo- 

 sperm, the disparity being greatest the smaller the amount of moisture 

 employed in the experiment. The moisture determinations seem to 

 indicate that growth could not be secured with any degree of success 

 unless the moisture content in the embryo amounted to 03 per cent or 

 more. 



Taking the production of carbon dioxid as the measure of growth 

 during germination, the period of greatest activity with varying quan- 

 tities of moisture was generally found to be about the third or fourth 

 day, the exact time varying somewhat with different varieties. After 

 the jjoint of greatest activity was reached there was a gradual fall in the 

 amount of carbon dioxid exhaled until the end of the experiment. It 

 was also found that the highest moisture content of the embryo coin- 

 cided with the period of greatest activity in tlie evolution of carbon 

 dioxid. 



Effect of stem ringing on broad-leaved, deciduous trees, A. D. 

 ElCHARDSON {Trans, and Proc. Hot. ^Soc. Edinburgh, 20 {1895), IT, pp. 

 337-339). — A brief report is given of some experiments conducted to 

 ascertain the effect on broad-leaved trees which possess a well-defined 

 heartwood, as compared with those not possessing a duramen, by the 

 removal from their stems of a cylinder of bark along with a certain 

 amount of underlying wood. The trees in this experiment consisted of 

 2 maples, 2 beeches, 2 horse-chestnuts, 2 oaks, and 2 laburnums. From 

 one tree of each kind was removed a cylinder of bark and wood about 

 G in. long, with a tliickness varying with the different kinds of trees. 

 In the maple, beech, and horse-chestnut it amounted to one-half that 

 of the whole stem, including the bark. In the oak and laburnum it 

 consisted only of the bark and underlying sapwood. 



There was no perceptible effect on leaf production produced by tlie 

 removal of the bark only, nor was there any effect produced by the 



