744 EXPERIMENT STATION RECORD. 



iutegument increases the rapidity but not tlie total absorptive capacity. 

 Seeds nearly covered with water will become saturated, while if only a 

 small portion of the surface is exposed to water the amount absorbed 

 will be small, in some cases not sufficient to induce germination. 



The ability of seed to absorb watery vapor was studied, and it is 

 stated that they have considerable po^er in this respect, but the entirety 

 of the integument greatly reduces this absorption. The ability to 

 absorb vapor differs with individuals, and the vitality of the seed is 

 iniiuenced by such absorption. 



The splitting of the integument is not ])roduced by the swelling of 

 the embryo, nor is the radicle by simple pressure able to pierce the 

 walls of the seed coat. It is thought that some diastase is present to 

 aid in this process. 



Under the second head it was found that with some seed imbibition 

 of water i)roduced a swelling, while in other cases there was a contrac- 

 tion in volume. There is an expansion followed by a contraction with 

 seed having a thin integument which is capable of wrinkling. The 

 dilation is caused by the separation of the integument from the seed, 

 the rapid imbibition of water creating a space which is filled by gas. 

 Contraction in volume takes place during the imbibition by seeds hav- 

 ing hard seed coats, akenes, and injured seed. It is caused by chemical 

 combinations formed by the water and the reserve material of the seed. 



In the process of ripening the drying of the seed is due to a regular 

 transpiration, and not simple evai)oration. 



The action of salts on the form and structure of plants, C. Das- 

 SONVILLE {Rei\ gen. Bot., 8 {1896), Nos. 91, pp. 284-29-1, ph. 2, figs. 2; 

 92, pp. 321-336, pis. 2, figs, ^'j.— The author has studied the effect of 

 various salts when supplied to plants growing in water cultures, com- 

 paring the development of plants which were supplied with certain 

 salts with the development of plants grown in distilled water and iu 

 Knop's culture solution. This solution is prepared after the following 

 formula : 



Calciam nitrate grams . . 1. 00 



Potassium phosphate do . . . .25 



Potassium nitrate do. . . .25 



Magnesium sulphate do . . . .25 



Iron phosphate Trace. 



Water liter.. 1.00 



In the first i)art of these experiments comparisons were made be- 

 tween plants grown in this solution and those grown in distilled water. 

 The plants experimented with werevlupines, rye, wheat, maize, potatoes, 

 buckwheat, hemp, mustard, flax, sunflower, rape, gourds, and castor 

 bean. The only plants reported upon are lupines and rye. The differ- 

 ence in the morphology of the different parts of the plant is given in 

 considerable detail. 



In general, the Knop solution increased the number and diameter of 

 the vessels and retarded their lignitication iu all parts of the lupine. 



