“The clay soil really needs air.  The good bacteria will not work without this.  So spade the soil up in the fall, and leave it weathering in huge lumps.  Sand or ashes added in the spring helps the air question too.  A sprinkling of lime over the surface tends to sweeten the entire soil; for clay soil, so often too wet, is liable to get sour.  Lime also adds another plant food called calcium.  It would not be bad to add some humus in order to have an even greater supply of nitrogen.

“The lime soil, light and sweet, needs humus too.  It should have this to add body and ability to hold water.

“Sometimes it is well to add in the spring a sprinkling of phosphates; that is a chemical fertilizer.  Chemical fertilizers are like tonics to the soil.

“All this very briefly puts us in touch with plant foods.  I think you all know from your school work that plants take their foods in liquid form.  These solutions of foods are very, very weak.  That is another reason why we should see that, if possible, there is plenty of nourishment available in the soil, and plenty of water too.

“These bean roots and rootlets show the feeding area or places of plants.  Notice the small roots which apparently have a fringe on them.  These fringes we call the root hairs.  These absorb, soak up the dilute food which is in the soil.

“It is very wonderful what power they have of penetrating the soil.  See the bit of blotter I have put down the path of one bean’s root course.  It would seem to shut the rootlets entirely off from the soil.

“Jay will gently press the bit of blotter away from the soil.  See here and there how these root hairs have wound their way through the blotter to the soil, their feeding place.  It is well that plants have this power of seeking and finding food.  Because it greatly increases their food chances.

“So much very briefly for plant food.  I have not told you very much to be sure, but it is quite enough, I think, for a ‘starter,’ I wish to tell you a bit about the plant itself soon.  A few experiments may liven up the subject.  So I shall ask Josephine, Miriam, and Ethel to attend to those for us.  We can take turns at demonstrating as Jay and Albert have to-day.  So you girls must remember to drop in to see me—­say, Wednesday of next week.”

III

SEEDS

Now before we begin just have a look at these geraniums.  They have turned entirely around again and are looking out of the window at the sun.  The power which plants have to move is very clearly shown, is it not?  I am going to talk a little this afternoon about seeds.

“Any reliable seed house can be depended upon for good seeds; but even so, there is a great risk in seeds.  A seed may to all appearances be all right and yet not have within it vitality enough, or power, to produce a hardy plant.