294 Elementary Principles of Agriculture 



Hydrogen. A chemical element. It is present in water and all living 



substances. 



Hygroscopic. Holding moisture as a film on the surface. 

 Hypha (plural, hyphae). The separate threads of the plant body of 



fungi. 



Inoculate. To infect with a disease. 

 Inorganic. Matter which has not been elaborated into plant or animal 



substance. 



Insectivorous. Eating insects. 

 Insecticide. A poison used to kill insects. 

 Internode. The space between two nodes of a stem. 

 Inter-tillage. Tillage between plants. 

 Kainit. A salt of potash used in making fertilizers. 

 Kernel. A single seed, as a grain of corn, wheat, etc. 

 Kerosene Emulsion. See Appendix B. 

 Larva (plural, larvae). The worm-like stage in the development 



of insects. 

 Layer. A part of a plant that has been bent down and covered with 



soil to stimulate the formation of roots. After the roots are 



formed, it is separated from the parent plant. 

 Legume. A plant belonging to the same family of plants as the pea, 



bean, alfalfa, clovers, etc. 

 Lichen. A kind of fungus plant that grows associated with algae. 



Very common on stones and bark of trees. 

 Loam. An earthy mixture of sand and clay, with some organic 



matter. 

 Magnesia. A substance containing the chemical element magnesium. 



It is similar to lime. 

 Microbe. A general term applied to all plants or animals that are 



so small that they may be seen only by aid of the microscope. 

 Mildew. A cobwebby fungus on the surface of diseased or decaying 



things. 

 Mold, or Mould. Used in the same way. Mold occurs only on dead 



substances. 



Mulch. A loose covering of straw, leaves, or soil, to retard evapora- 

 tion from the soil. 

 Nitrate. A compound having NO 3 combined with a basic mineral 



substance; a salt of nitric acid. 

 Nitrification. The changing of nitrogen into nitrates. 

 Nitrogen. A gaseous chemical element composing 79 per cent of the 



