BOTANY. 721 



The roots of several apple trees were examined, one of which had 

 been planted 7 years on a rather poor soil. The larger roots varied 

 from 1^ to 2 in. in diameter, and the root system extended horizontally 

 on one side a little more than 12 ft. and vertically about 9 ft., from 

 which it appears that the tree drew its sustenance from a cylinder of 

 soil something more than 24 ft. in diameter and 9 ft. in depth, repre- 

 senting a total volume of about 150 cubic yards. Comparisons were 

 made between a seedling tree 4 years old and 2 root-grafted trees 3 

 years from the graft. The difference in the forms of the crown of the 

 root was found to be quite marked in the 2 methods of growth. In 

 the seedling no abnormal growth was perceptible, while in the part of 

 the trees grown from root grafts the growth of the crown was abnormal. 

 In the seedling a strong tap root was developed, while in the root grafts 

 there was no semblance to a tap root. If these abnormal growths gen- 

 erally follow root grafting, the author suggests that some substitute for 

 this system might prove acceptable in the northwestern States. 



Evaporation and plant transpiration, W. Maxwell {Jour. Amer. 

 Chem. Soc., 20 (1898), No. 7, pp. 469-483).— The author reports experi- 

 ments on the amount of moisture directly evaporated from the soil, and 

 the relative proportion that escapes by transpiration from sugar cane 

 during the different periods of growth. The methods followed in the 

 experiments were briefly as follows: One hundred and twenty-five 

 pounds of a particular soil was placed in each of 2 tubs with per- 

 forated bottoms, over which a piece of linen cloth was laid before put- 

 ting in the soil to prevent the earth falling through or blocking up the 

 holes. When filled with soil the tubs were set into galvanized iron 

 pans containing water which was kept at a constant level. The pans 

 were covered with moisture-proof glazed cloth to prevent any evapora- 

 tion from the water surface. All evaporation of water would neces- 

 sarily have to take place through the surface of the soil and the 

 transpiration of the plant. In one tub 3 pieces of seed cane were 

 planted, while the other was kept as a check. The tubs were placed 

 upon a veranda having a southern exposure with a strong light, but 

 protected against rainfall. The mean outdoor and indoor evaporation, 

 humidity, direction of the wind, and other meteorological data were 

 secured, which, together with the amount of evaporation from the 2 

 tubs, is tabulated. 



The experiment was continued for 7J months. The water evapo- 

 rated from the soil in tub No. 1 was 83,140 gm., and the water evapo- 

 rated from the soil and transpired by the cane in tub No. 2 was 

 107,250 gm., thus showing that the cane transpired during the period 

 indicated 84,110 gm. As the total amount of dry matter produced 

 during the period of growth was 568.9 gm., for each gram of water-free 

 sugar cane material produced 147.8 gm. of water was transpired. The 

 amount of water transpired by the plant is given by monthly periods, 

 and from the data collected the author thinks some important conclu- 

 sions relative to practical irrigation could be drawn. " To apply the 



