134 



QUERIES AND ANSWERS. 



Orig^in of 

 some Double 

 Flowers. 



Soil 

 £xhaustion. 



Loss of 



Soil 



Fertility. 



Koots, 



Various 



ICiuds. 



gardeners setting more than twice as many as others, dependent upou 

 strength of soil. The following is an approximation of the quantities : 



Cabbage 10,000 



Cauliflower 10,000 



Pepper 7,000 



Tomatoes 3,000 



Egg Plant 3,000 



834. Q. How do gardeners obtain double flowers of ornamental plants? 

 A. A double flower is one in which some or all of the stamens or pistils 



are changed to petals or flower leaves, or a flower in which the normal 

 number of flower leaves is greatly increased. The change results in the 

 loss of power in the plant to develop seed. It is often entirely brought 

 about by starvation of the growing plant, sometimes by debility in the 

 seed, a consequence of age or exposure. 



835. Q. What proof is there that plants exhaust the soil ? 



A. A good proof is that the soil in pots or tubs is exhausted by plants 

 remaining in the pots or tubs for a considerable time, the effect being 

 smaller foliage and flowers, and weak branches. As these conditions can 

 be relieved by the application of manure it is clearly demonstrable that 

 the soil was exhausted. 



836. Q. How do soils become exhausted ? 



A. Partially by the loss of nitrogen in the soil. Large amounts of 

 nitrogen are lost by natural soil drainage, the rains carrying down the 

 nitrogen to a depth beneath the reach of roots. This especially occurs on 

 fields not covered with crops, for when so covered the crop evaporation 

 keeps water up near the soil, but when bare the water sinks, taking the 

 nitrogen down. This is one argument for catch crops, that is, temporary 

 crops, quick growers, as Scarlet clover, or Cow peas. These cover the 

 ground, stopping drainage, and the leeching away of nitrogen, and if the 

 catch crops are well selected they add more nitrogen through their 

 growth. Nitrogen also becomes exhausted partially through a diminution 

 in humus, which by a chemical action and change aff'ords nitric nitrogen. 

 Nitrogen, however, is not the only food constituent which subsoil drain- 

 age removes, for there may be a loss of phosphoric acid and potash also. 



837. Q. What are the names and distinctions of the fleshy, earthy 

 stems of plants ? 



A. They are all classed as roots, but they are distinguished from roots 

 proper by producing regular buds or bearing scars indicating formed 

 leaves. A rhizom is a thickened starchy root stem, as illustrated by the 

 calamus or by the wire grass. A tuber is an enlargement of a bud of an 

 underground stem illustrated by the white potato. All tubers are rich 

 in starch. A bulb half in and half out of ground is an abbreviated stem, 

 formed of the basis of thickened leaves termed scales, illustrated by the 

 onion. Bulblets are small bulbs oflTset from large bulbs, often seen on 

 the outside of hyacinths. Corms are like bulbs but solid or without 



