92 A GRAIN OF BARLEY, 
From books and drawings only it is impossible to obtain 
perfectly clear and complete ideas upon these points, and I 
wish to impress upon your minds the necessity of studying the 
actual objects themselves if you wish to make yourself fully 
acquainted with the meaning of everything you can see in the 
ripe grain of barley. Procure specimens of the flower and 
grain at different ees of growth, and, after having divested 
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DIAGRAM OF A VERY SIMPLE FLOWER IN LONGITUDINAL SECTION. 
a, transverse section of an anther before its dehiscence ; 4, an anther dehiscing longi- 
tudinally with pollen ; c, filament ; d, base of floral leaves ; ¢, nectaries ; 7 wall of carpels; 
g, style; , stigma ; z, germinating pollen- grains ; 2, 4, m, a pollen-tube which has reached 
and entered the micropyle of the ovule; z, funicle of ovule; 0, its base; f, outer; g, inner 
integument ; s, nucellus of ovule; ¢, cavity of the embryo. “Sac; , its *basal portion with 
the antipodal cells ; v, synergidz ; 2, oosphere (after Sachs). 
them of their protecting glumes, immerse them in strong alcohol 
for a time to harden them, then put them in a mixture of 
alcohol and glycerine and allow the alcohol to evaporate 
spontaneously. In this way you will obtain the delicate little 
specimens in a semi-transparent state, and in a condition 
admirably suited for cutting into extremely thin sections for 
the microscope. 
I will now describe briefly the structure of the flower and 
