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MAIZE 



CHAP. 

 IV. 



76. The Silk. — The style or " silk " is a long, terete, hollow 

 tube, bifid at the end (Fig. 52A) and it contains a viscous sub- 

 stance. When receptive, the silk is exserted from the apex of 

 the ear to receive the pollen, and may then become 6 to 1 2 

 or more inches in length. After pollination the silk dries 

 up, but persists. If pollination is prevented or is incomplete, 

 the silk continues to grow to an unusual length, and remains 

 green much longer than otherwise. Under a lens the silk is 

 seen to be covered with short, branched hairs, on which the 

 pollen grains are caught. 



Fig. 52. — The style or silk (much magnified). A, Showing bifid end, and 

 pollen grains caught among the hairs. B, Hairs magnified, showing cells and 

 nuclei. 



The silks do not all mature at the same time ; those at the 

 base of the ear develop first (Fig. 32); then those from a 

 little higher up, and finally those from the tip. It takes about 

 a week for all the silks on an ear to mature (Figs. 30 and 31). 

 This progressive development appears to be one of nature's 

 ways of ensuring the pollination of at least some of the ovules. 

 It sometimes happens that there is not sufficient pollen avail- 

 able at the appearance of the earliest or latest silks, which 

 results in the production of incompletely filled ears or "nub- 



