22 
PREVIOUS SOAKING OF THE SEED IN WATER A MEANS OF REDUCING 
THE INJURY FROM COPPER SULPHATE. 
On March 22 three lots of seed were placed between layers of moist 
blotting paper and kept under a bell jar for forty-eight hours, or until 
germination had well begun, as was shown by the protrusion of the 
radicles to a distance of 1 or 2 mm. _ In this condition the germinating 
seeds were treated for thirty minutes with 3, 5, and 10 per cent solu- 
tions of copper sulphate, after which, without drying, the seeds were 
planted in sand and covered as before. The object of this experiment 
was to test the claim of Otto that ‘“ the active protoplasm of the cell is 
able to resist the osmotic entrance of copper.” The plumules began to 
appear the Second day after planting, or the fourth day from the begin- 
ning of the experiment. The detailed record of the germinations are 
as follows: 
Daily germination of oats treated after sprouting had begun. 
Strength of Fourth Fifth | Sixth Seventh | wee | Ninth Tenth Fifteenth 
solution. day. day. day. | 4 day. day. | day. — 
| | 
aipercent. =o... -5 6 | 49 68 | om 76 | 81 84 | ; 84 
5iper cent... ------- 4 16 - 45 | 52 | 5a 60 64 | 64 
10)per cent_....---- 0 | 2 32 | 40 | 43 | 44 45 | 48 
| | 
By comparing the total number of germinations with the lots of seed 
receiving the same treatment without the preliminary germination, as 
is shown on page 18, under the thirty minutes’ treatment, it will be seen 
that in the lot of dry seed treated with a 3 per cent solution 39 per cent 
germinated, and in the lot where the seeds began to sprout before 
treatment 84 per cent germinated, or a gain for the latter lot of 115 
per cent. For those soaked in the 5 per cent solution the figures for 
the respective lots were 26 and 64 per cent, a gain in this case of 133 
per cent. Comparing the lots soaked in the 10 per cent solution, the 
germinations were 19 and 48 per cent, a gain of 148 per cent in favor of 
the seeds whose germination had begun before their treatment with 
the fungicide. 
Judging from the greatly increased percentage of germination shown 
by the lots of seed that were sprouted before soaking in the copper 
solution, it would seem that the active protoplasm in the embryo is 
able to withstand the corrosive action of the stronger solutions of cop- 
per sulphate to a much greater degree than is possible for that in the 
dormant embryo. However, when the root systems and aerial portions 
of the plants were examined it was seen that but little, if any, advan- 
tage could have accrued to the plant from using the fungicide at the 
later time. In only two or three cases could it be said that there had 
been any development of primary roots, and in many instances the 
plants died before lateral roots were put out for their support. The 
aerial portions of the plants showed the same dark bluish-green color 
—EE 
