A. St Clair Caporn 279 



SUMMAKY. 



In the first part of the paper the parents are fully described ; an 

 accurate method of measuring and tabulating glume lengths explained ; 

 and it is shown how in the F^ generation a marked change in the 

 average glume length of homozygous ' longs ' as compared with the 

 average of the parent, T. polonicum, under equal conditions persists 

 right through into the ^3 generation. 



The second half is concerned with the purple pericarp colour, — the 

 manner and extent of distribution in the tissues, its development and 

 detection in minute quantities, and the inheritance. The latter is dis- 

 tinguished by one cardinal and unaccounted for anomaly : segregations 

 analogous to the F^ segregation have not been found in the F3 gene- 

 ration. Streaking, a character which suddenly appeared in the F^ 

 generation, has resemblances to particolouring in maize. These are 

 discussed. 



Various cultures have been stabilised in respect of colour and glume 

 length. 



EXPLANATION OF PLATES. 



PLATE XIII. 



Fig. 1. Ear of T. polonicum. Spikelets in frontal view. Natural size. 

 Fig. 2. „ „ „ lateral ,, „ 



Fig. 3. Ear of T. eloboni. „ ,, ,, „ 



PLATE XIV. 



„ . ^ . , rr, , . T ( a. 32 X 4i mms. 



Fig. 4. a, a'. Extreme forms of T. polonicum glumes ^ , „, . 

 ° (a. 21x4 ,, 



b. Typical T. elohoni glume. 10 x 4 mms. 

 Fig. 5. An Fi ear. Spikelets in lateral view. Natural size. 

 Fig. 6. a. 'Long' type of intermediate glume. 17|x4|mms. 



b. 'Average' ,, ,, „ 16x4^ „ 



c. 'Short' ,, „ ,, 14^x4 ,, 

 Fig. 7. a. T. polonicum grain, llj x 3^ mms. 



b. Fi grain. 10 x 4 mms. 



c. T. eloboni grain. 9x3^ mms. 

 Fig. 8. Colour types. 



a. T. polonicum grain \ 



b. ' Flushed ' grain I vt i. 1 1 



, , . > Natural colours. 



c. 'Streaked gram I 



d. Faintly 'streaked' grain J 

 b', c', d'. Acid colours. 



19—2 



