especially significant. (Under the tip cap, as is evident when the tip cap is broken off, is a 

 small black spot. This black spot is entirely normal and has nothing to do with the discol- 

 oration mentioned above.) The surface of the cob should be bright, clean and chaffy. Cut 

 one-half point for each ear showing defective color or luster. 



(b) Condition of Hull. (5) Germination tests show that kernels with blistered hulls 

 usually fail to grow or are of low vitality — the lack of vitality varying with the degree of 

 blistering. A tiny blister at the top or a little wrinkling over the surface of the germ- 

 depression should not be mistaken for blistered hull. Usually when a kernel is definitely 

 blistered it is seen on the back and edges of the kernel. Cut one-half point for each ear hav- 

 ing kernels with blistered hulls. 



(c) Condition of Germ. (15) The germ should be plump, bright, waxy, and of a creamy 

 or light yellow color. A pale, shrunken, dull-appearing germ indicates poor vitality. A dark- 

 colored one indicates injury from frost or moisture or from both. Cut one and one-half 

 points for each ear having kernels with poor germs. 



(d) Freedom from Injury. (5) There should be no missing, nor mouldy, cracked or oth- 

 erwise injured kernels — the two kernels removed for study excepted. Cut one-half point for 

 each ten kernels missing or ruined for seed. Cut one-half point for each twenty kernels 

 slightly injured only at crown. 



7. ADAPTATION. (30) Adaptation, is of great importance in selecting seed corn and 



is indicated in part by the following: 



(a)* Size of. Ear. (10) For every ten inches less rainfall than forty inches, deduct one- 

 half inch from the standard length discussed in the footnote at the bottom of the page. Like- 

 wise deduct an additional one-half inch for every 25 days shortening of the growing season. 

 The approximate size of ear for any section may be determined after a moment's study of 

 Figs. 18 and 48, pages 45 and 72. To allow for local variations and other inaccuracies, it is 

 suggested that a deviation of one-half inch either above or below the standard determined 

 upon should be allowed before an exhibit be faulted for too great or too little size. 



Furthermore, the rules should not be applied except under the following conditions: 



First. The corn is of the dent type. , 



Second. The variety is normally one-eared. 



Third. The corn has the usual ratio of circumference to length — 3 to 4. For instance, 

 corn which is extremely slender for its length and has very short kernels may, even in dry 

 countries with a short growing season, be distinctly longer than the rule calls for. It will 

 be noticed, however, that as the ear becomes disproportionately long, the kernels are usually 

 abnormally shortened and the circumference becomes proportionately smaller. In other words, 

 in as far as the real size of an ear is made up of length, circumference and per cent of corn 

 on the cob, the ear though unduly long is, after all, practically normal in size. In exactly the 

 same way corn of unusually great diameter of ear and extreme depth of kernel may be grown 

 if the ears are at the same time abnormally short. 



Fourth. The corn when planted at the customary time needs the full growing season in 

 order to mature. 



Fifth. The corn is not grown in such a climate as that of the Northeastern States where 

 sunshine and summer heat have not the intensity of the corn belt. In such sections, espe- 

 cially near large bodies of water, the ears seem to be somewhat smaller than rainfall and 

 length of growing season would indicate. 



*In a previous lesson it was shown that there is a definite relation between climatic factors and size of ears 

 in corn. Though this relation holds true in a general way, an exact measure of the effect of climatic factors upon 

 size of ear is quite impossible. Nevertheless for the purpose of scoring, it will be necessary to suggest definite 

 limits as to the size of ears adapted to various corn-growing sections of the United States. 



It is probably true that southern Indiana and Illinois, with a rainfall of forty to fifty inches and a growing 

 season of from 175 to 200 days.^ as measured between frosts, is climatically the most favorable part of the corn 

 belt. Certain other sections, it is true, have longer growing seasons and more rainfall, bttt these sections have cer- 

 tain difficulties which tend to offset their apparent advantages. Chief among these disadvantages is the fact that 

 rainfall is not so well distributed for corn as in the best part of the corn belt. Southern Illinois and Indiana are 

 probably growing about as large an ear as is profitable to grow anywhere. Assuming that the average size of 

 the better ears in this section have for their maximum a length of ten inches and a circumference about equal 

 to three-fourths of the length, this standard becomes basis from which to roughly approximate sizes adapted to 

 other corn -growing sections of the United States. 



76 



