68 



THE WHEAT PLANT 



then showing three green shoots above ground, one on each side of the 

 main stem, arranged in alternate order, i.e. with a divergence of or 

 1 80. Two more shoots soon spring from the primary stem above the 

 first pair, and about the same time each of the two first branches give rise 

 to two alternate branches of the second order arranged in a plane at right 

 angles to that of the first pair, the plant then consisting of nine shoots, 



the relative position of which 

 can be easily recognised in 

 upright growing spring 

 forms of wheat : in the winter 

 types, however, which for a 

 time are decumbent, the 

 shoots soon bend out of the 

 planes in which they arise 

 and appear arranged more 

 or less in a semi-circle close 

 to the ground : the arrange- 

 ment of the first nine axes 

 of the plant is indicated 

 in Fig. 63. Additional 

 branches may arise later, not 

 only on the primary axis, 

 but on stems of the second, 

 third, and higher order, the 

 plant ultimately consisting 

 of a very large number of 

 crowded leafy shoots, with 

 short unexpanded inter- 

 nodes, the whole forming a 



FIG. 62. Longitudinal section through a young plant . r. ,1 --11 



14 clays old (x 25). s , Scutellum ; o/coleoptile ; dense tuft > the vlslble P arts 



b, bud in the axil of the coleoptile ; c, bud in the being, of course, the blades 



axil of the first foliage leaf ; n, bud in the axil of the r i_ i u 



second foliage leaf ; x, terminal bud ; r, adventitious ot the leaves With portions 



root - of their sheaths, the axes or 



stems from which they spring being short and hidden from view. 



Schoute's method of indicating the various axes or branches of the 

 plant is convenient. The primary axis is denoted by the figure i, its ist, 

 2nd, 3rd . . . branches by the figures n, 12, 13 ... respectively. 



Similarly, the figures i, 2, 3 ... may be joined to these to indicate 

 the ist, 2nd, 3rd . . . branches of these axes : e.g. 132 denotes the 2nd 

 branch of the 3rd branch of the primary axis (Fig. 64). 



The leaves on the several axes may be expressed in the form of a 

 fraction, the denominator of which denotes the axis, the numerator re- 

 ferring to the number of the leaf on that axis : e.g. 'f indicates the 2nd 



