1918] Waynick: Antagonism and Cell Permeability 141 



Selected seeds were distributed over the toweling so that about two 

 hundred were placed on an area of the size indicated above. Another 

 Layer, made up of several sheets of toweling, was then laid on the 

 seeds and the whole thoroughly soaked with water. The water was 

 allowed to evaporate gradually until the paper was but slightly moist 

 to the touch and the water relation then maintained constant until 

 the seedlings were transferred to the solutions. If the paper is kepi 

 too moist the growth of molds is often very abundant, but with a low- 

 moisture content no trouble was experienced from this source. By the 

 time the roots were a quarter of an inch long, the upper layer of 

 paper was supported two or three inches above the seedlings. This 

 procedure permits of a straight growth of the shoots, which is of con- 

 siderable importance in placing the seedlings in the corks. The seed- 

 lings were transferred when the shoots were about an inch and a half 

 in length. The paper in which the roots are grown, tears apart readily 

 without injuring them in any way, the oilcloth not permitting their 

 downward penetration. There is no contact with metal containers 

 at any time, the apparatus required is practically nothing, the time 

 period is short — about six clays under greenhouse conditions — and 

 strong seedlings are obtained which can be transferred to any contain- 

 ers without injury. 



The containers used were quart jars of the Mason type, each 

 holding approximately 950 c.c. of solution. The inside of each jar, 

 as well as that of the bottles for the stock solutions, was coated with 

 a layer of paraffin so that the solutions were never in contact with the 

 glass. The outside of the jar was covered with black paper to exclude 

 light, the black surface facing the glass. Flat corks, having a diam- 

 eter of three and a half inches, were used to support the seedlings. 

 Each cork had seven holes, one in the center through which distilled 

 water was added to maintain the volume of the solution as nearly 

 constant as possible, and six equally spaced, one and a quarter 

 inches from the center, for holding the seedlings. After the holes 

 were made the corks were soaked in boiling paraffin. 



To introduce the seedlings the corks were turned upside down, 

 supported by the rim of the jar, and the shoots stuck through the 

 holes prepared for them and held in place by a small piece of cotton. 

 On turning the corks over the seedlings were in their proper position 

 without being in the least injured, for there was no necessity for 

 touching the roots at any stage since the plant was always picked up 

 by the seed coat. The method suggested by Tottingham 23 was tried. 



