62 



The large fleshy leaves lie as shrunken leathery strips at the base of the 

 stalk. The mother plant is dead. The blooming period of the nasturtium 

 and pansy is prolonged by cutting the flowers, thus preventing the weakening 

 of the plant through seed parasitism. All this is not without its lesson 

 in modern field practice. The farmer no longer selects his seed corn from a 

 plant that has not been able to survive the need of its progeny for organic 

 materials. Such a plant is either constitutionally weak or diseased. Mature 

 ears on a green stalk show vegetative strength and, usually, freedom from 

 disease which presage embryo vigor and proper food reserve. 



Embryo and endosperms are enveloped by the two seed coats to which, 

 in our cereals, the wall of the ovary is added. These coats when intact 

 offer an effective protection against mechanical injury and fungus attack. 

 The organic materials of the endosperm furnish ideal foods for a number of 

 the fungi causing severe injury or death to very young seedlings. Corn 

 with distinctly chaffy indentation is especially prone to fungous attack. 

 (Figures 1 and 2.) There are several reasons for this and the discrimination 

 against this character in the Utility Score Card is, in my opinion, justifiable. 

 Even in the case of some strains of corn where it is apparently an inherited 

 character, it is objectionable for the reason that the coats are there very 

 easily injured, resulting in fungous infection, with the consequent decrease 

 in vigor to the germ or even early death. Kernels of this nature usually 

 have a very starchy endosperm, the result of strain or inheritance, or because 

 they are imperfectly matured. In either case they are more likely to fungus 

 attack than are kernels with a larger quantity of horny endosperm. In this 

 connection corn harvested in different stages of maturity; namely, milk, 

 dent, and mature, shows interesting results. Soaked in water the amount 

 of material leached increases from the mature, where it is very slight, to 

 the milk stage, where it is very marked. On the germinator the sprouts 

 of the mature corn are vigorous, the percent germinating high, and little 

 or no fungus develops. In the milk stage the germination under similar 

 conditions is more rapid largely because of rapid water absorption the 

 sprouts are slender and weak, the percent germinating low, and fungus 

 abundant. (Pig. Ill, IV, V.) 



NEED AND FUNCTION OF WATER. 



The living substance can manifest its properties and perform its func- 

 tions only in the presence of water. This plays an important role in all 

 vital activities and enters into the physical-chemical structure of the proto- 

 plasm. As the most universal solvent in nature, it carries to the cell the 

 materials for elaboration and eliminates from the cell the products of 

 destructive metabolism. It is the vehicle in which are carried the materials 

 from the mother plant to the developing seed. The quantity of water present 

 in a member of an organ roughly determines its state or phase of vital 

 activity. In active life the quantity varies from 40 to 98 percent. In the 

 air-dry seed, as you know from the tables used in the commercial grading 

 of grain, it is much lower. In fact, it may be reduced in some seeds to 

 2 percent or lower without causing death, although not without injury. The 

 rapid increase, by small quantities of water, in the vital activities as 

 measured by the respiratory process is shown by the figures below: 



Respiration of Haynes Bluestem wheat, incubated at 100 F. for four 

 days. (After Bailey and Gurjar.) 



Moisture Carbon dioxide in milligrams respired 



PerCent. in 24 hours for each 100 grams 



of dry matter. 



12.50 0.54 



13.93 0.65 



14.78 0.86 



15.42 1.62 



16.08 2.88 



16.65 6.86 



17.07 11.72 



Stored grain of relatively high water content still further increases the 

 water present through the metabolic water from the respiratory process. 

 This results in a lowering of vitality, fungous attack, and ultimately death. 

 The losses incident to the transportation and storage of grain are avoidable 



