3G6 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



sorb water and lime salts through their leaves (Chem. Cen* 

 traXblatt, 1870, pp. 250, 275, and 808). 



ROOT-DEVELOPMENT OF PLANTS. 



The study of the root-development of some of our more 

 important agricultural plants is receiving increased attention 

 of late. Very interesting observations have been made by 

 Nobbe, Ilaberlandt, and Thiel. Fraas has published a little 

 work on the subject ; Mtiller has given a resume of the main 

 points of the present status of our knowledge of the subject 

 in the LandioirtJischaftUche JaJirbucher y and, finally, Yon 

 Xathusius and Thiel have issued a series of six charts, con- 

 taining no less than fifty-three very fine photographs of roots 

 of various plants as they actually grow in the soil. These in- 

 clude views of the roots of corn, barley, pease, Jerusalem arti- 

 choke, potato, and sugar-beet, from which the soil had been 

 removed so as to allow of their being photographed as 

 they grew. They show that while the fine roots penetrate 

 much deeper into the soil than many suppose, yet by far the 

 larger bulk are within a few inches of the surface, and that 

 there most of the feeding of the plants through the roots is 

 done. 



Heinrich reports some interesting experiments on the de- 

 velopment ot roots of barley, oat, and pea plants. The plants 

 w r ere grown in boxes four meters (about thirteen feet) deep, 

 filled with fine garden earth. The oat roots penetrated 2.27 

 meters; those of barley, 1.9; and of pease, only 0.52 meters. 

 The soil was carefully washed away from the roots, and the 

 latter, as well as the tops, weighed. The weight of the roots 

 of oats was about two thirds that of the tops, without seed; 

 those of barley weighed about one third, and of pease one 

 fifth, as much as the tops. 



Fremy and Deherain "find that sugar-beets grown in saline 

 solutions, instead of sand moistened with the same, lived; 

 but instead of producing one laro-e central sugar-forming 

 root, they simply formed a mass of nearly equal rootlets. 



MANURES. 

 Phosphatic Fertilizers. 



Dr. Voelcker has continued his reports on these materials, 

 giving analyses of over fifty samples of phosphatic guanos. 





