Jan. 8. X920 Lime and Sodium-Chlorid Tolerance of Wheat Seedlings 349 



As soon as the radicles appeared, usually at the end of 24 hours, the 

 seeds for the sand or soil cultures were taken out and planted. The 

 pans were allowed to stand until the shoots of the other seeds had 

 reached a height of about i cm., when they were transferred to the 

 culture bottles. In addition to the sand and solution cultures, this 

 experiment included a series of bottles filled with very fine soil — a vol- 

 canic ash obtained from Jamaica, consisting of about 98 per cent of 

 iron and aluminum oxid, principally iron. The bottles of soil and 

 sand were watered with these solutions before planting until the drainage 

 titrated the same for chlorid as did the original solutions. This took 

 about 2 days in the soil cultures, since only about 250 cc. of the solution 

 moved through the clay in an hour. With the sand it took a much 

 shorter time. 



On March 5, when the plants were 8 days old, they were photographed 



(PI. 39). 



As in Plate 38 it will be seen that the toxic action of the sodium chlorid 

 was first noticeable in the solution cultures, even in the 500 parts per 

 million solution, the lowest concentration; and the effect was more and 

 more appreciable, especially upon the root development, as the concen- 

 tration increased. It was not noticeable in the sand cultures in the lower 

 concentrations, in which the root development showed no marked differ- 

 ence until a concentration of 2,000 parts per million was reached. With 

 the soil cultures, no toxic effect of the sodium chlorid on the growth of 

 the plants could be seen, even in the highest concentration. In fact, 

 the plants growing in the soil and watered almost continuously with a 

 4,000 parts per million sodium-chlorid solution grew as well as, if not 

 better than, those growing in the same soil and watered with distilled 

 water. The only noticeable effect of the sodium chlorid upon the soil 

 cultures was the tendency to cause lodging, especially as the plants 

 grew older, this tendency increasing with the amount of sodium chlorid. 

 This is shown in Plate 40, A, which shows the plants when 9 days old. 



SERIES 3 



On March 12 another set of solution, sand, and soil pots was started, 

 with concentrations of sodium chlorid running from 1,000 to 4,000 

 parts per million. On March 15 one plant was withdrawn from each 

 group where the highest concentration was used and a photograph was 

 made. The 3 -day-old seedlings which had been grown in 4,000 parts 

 per million solution (PI. 40, B) were so small that they were still depend- 

 ent upon the seed and had not yet begun to feed upon the solution to 

 any appreciable extent. It was evident that the effect of the soil was 

 manifested upon the young plant at a very early stage in its life history. 



