144 



Journal of Agriculture, Victoria. [10 March, 1916. 



Fig. 1 is a diagrammatic represeutation of one of the ears of Federa- 

 tion wheat examined, showing the position of each gram in tlie ear, 

 and giving its weight in milligrammes as obtained by the microbalance, 

 and tlie weight of the ears obtained by growing the resultant plant m 

 a centgener plot. 



A perusal of the figures representing the weights of the individual 

 grains show that the intermediate grains of each spikelet are of con- 

 siderably less weight than those of the outside grains of the same 

 spikelet. Further, it will be noted that the grains towards either 

 extremity, and particularly the apex, are also undersized, ana on tlie 

 average produce relatively small yields. 



These points are more strikingly illustrated in Figs. 2, 3, and 4, 

 where the weights of individual grains in milligrammes have been plotted 

 against their position iu the ear. 



They represent typical ears with maxima of 2, 3, and 4 grains per 

 spikelet respectively. 



The grains taken from the same spikelet are connected by faint linss, 

 and those from the right and left spikelets are denoted by small squares 

 and circles respectively. The dotted line represents the general trend 

 of the weights from the base to the apex of the ear. As already noted, 

 there is an increase in the weights of kernels as we pass from either 

 extremity to the middle of the ear. 



In Figs. 3 and 4 the intermediate grains have been plotted separately 

 from the outside grains of the corresponding spikelets, and are connected 

 in the diagrams by faint dotted lines. The graph shows clearly the 

 lesser weights of the median grains as compared with the adjoining 

 grains of the same spikelet. 



It is obvious that the weight of the ears produced show considerable 

 and erratic variations in spite of the elaborate precautions to insure 

 uniformity of growing conditions ; but, by taking the average of a 

 number of experiments, these individual fluctuations do not prevent 

 definite conclusions being arrived at. 



In order to compare the relative germinating capacity and 

 prolificacy of the median grains and the other small grains at the base 

 and tip with that of the remainder of the grains of the ear, the results 

 as obtained from three of the typical Federation heads which were 

 dissected may be quoted. As indicated above, each grain was planted 

 in recorded positions in centg?ner plots, and the weight of ears from 

 each plant obtained after harvesting. 



The results are summarized in Table I. : — 



Table I. 



Comparison of Yield of Produce from Median Grains avith that from 

 Heavy Grains avhxch ordinarily compose First Grade Wheat. 



