168 Journal of Agtncidture, Victoria. [10 March, 1916. 



VARIATIONS LY THE PLAXTS FROM THE SAME 

 HEAD OF WHEAT. 



By Alfred J. Ewart, D.Sc, Ph.D., (i;c., Government Botanist of Vic- 

 toria, and Professor of Botany and Plant Physiology in the Mel- 

 bourne University. 



In 1914, Mr. Adcock drew my attention to the fact that Mr. Whelan, 

 at Rutherglen, had observed variations in the rate of germination of 

 grains from the same head of wheat, the more rapid germination ap- 

 pearing to be shown by the grains from the middle of the head. Taking 

 single grains, how.ever, the rate of germination appeared to fluctuate so 

 much at different parts of the head as to render it doubtful whether the 

 variation was real or apparent only. 



AVERAGE RATE OF GERMINATION 

 I GRAINS FROM II. FROM 



' APEX SINGLE HEAD SEVERAL HEADS 



BASE 



Accordingly, tes.ts were carried out at the University under fully 

 controlled conditions in a large wire cage used for wheat breeding. Two 

 diagrams were made on paper corresponding to each wheat head used. 

 The grains were removed singly and planted an inch deep with the aid 

 of a marker. The times of germination in days were marked on the 

 duplicate diagram, those first to germinate being marked 1, those 

 germinating three days later 3, and so on. The grains in each successive 

 pair of right and left spikelets were marked 1st row, 2nd row, 3rd row, 

 &c. The total germination figures were divided by the number of grains 

 in each row. A diagram showing the germination figures for a single 

 head is shown (Fig. 1), and also the germination averages for successive 

 rows of a single head. (Column 1 of table.) 



These show a considerable amount of irregular variation, but if the 

 results from more than one head are averaged (Column II.), it can be 

 clearly seen that the germination is most rapid in the grains of the 



