APPENDIX B 115 



scanty and no account. Collect a variety of such green stuff as is 

 there. Collect a similar amount from the most productive soil in the 

 community. Feed these foods, in equal weights, fresh or quick dried, 

 along with water, to a couple of rabbits or guinea pigs for six weeks. 

 Does the quality of soil have anything to do with nutrition ? 



Very likely, the plant species from the two soils will be different. 

 This, of course, introduces another variable factor into the experi- 

 ment, so that the conclusion must consider the fact that some species 

 may not be basically as nutritious as others, even on good soil. How- 

 ever, it is a general fact that poor soils cannot produce highly nutri- 

 tious plants. 



CHAPTER III 



(1) Succulence may be demonstrated by comparing the chewing 

 qualities of celery, which is fibrous but still succulent, with a. tree 

 twig, which, though also fibrous, is never succulent. Even the wilted 

 or dried celery can be bitten through without difficulty. Try chewing 

 good hay, and straw. The relative values as feed should be apparent. 

 Microscopic examination of the two types of cells will reveal the great 

 difference in cell wall thickness. 



(2) Spread a bucketful of alfalfa hay and a similar amount of 

 straw in a dry, warm place. After a few days, when thoroughly dry, 

 weigh generous, equal amounts of each. Burn each separately and 

 completely on a piece of sheet metal. The material itself may be 

 ignited, but intense heat should also be applied beneath the metal. 

 Scrape off and weigh the mineral ashes on a delicate laboratory scale 

 (borrowed perhaps from the physics department.) 



Try this with celery and wood, particularly wood grown on eroded 

 land. 



Which material had the greatest mineral content? What was the 

 percent by weight of the soil's contribution as compared with the 

 contribution of air and water? 



(3) Take a field trip. Go to a wornout eroded field. Compaic 

 roughly the percentages of succulent and of woody plants. Observe 

 cattle grazing in a pasture. What sort of plants do they ignore ? Take 

 a close look at a good hayfield. Ask the land-user what makes it 

 good. What is the percent of woody plants there? Compare the 

 animals on the good and poor land as to appearance and muscular 

 development. 



(4) In plants, reproduction requires that the seeds have a supply 

 of starch, fat, proteins, vitamins and minerals to assure continuing 

 life. If you had to live on woody plants, what parts would you eat? 

 Do squirrels, deer, birds know that? Is this why we restrict our 

 eating of corn, wheat, rye, rice, etc., to the seeds? Try burning equal 

 dry weights of wheat grains and wheat straw. Where are the most 

 minerals found? Try the chewing test also. 



