164 



BOTANY OF CROP PLANTS 



What Is, the "Ear," Morphologically? — There are two 

 theories as to the morphology of the ear of corn. The view 

 of Hackel and of Harshberger is that the ear is the result of 

 a fusion of a number of two-rowed 

 pistillate spikes. Since each spikelet is 

 two-flowered, and the lower abortive, 

 there are often formed the two distinctly 

 paired rows. The cob is said to be 

 formed by the fusion of separate rachises. 

 Opposed to the above theory is that of 

 Montgomery, who holds that the ear 

 develops "directly from the central 

 spike of some tassel-like structure 

 similar to the well-known corn tassel." 

 His evidence for this belief may be 

 summarized as follows: 



1. He has found tassels in which a 

 few pistillate flowers were found on the 

 central spike, also tassels in which the 

 central spike had developed into a fair- 

 sized ear of corn. 



2. He observed a case in which the 

 lateral spikes as well as the central one 

 had developed pistillate flowers, form- 

 ing a number of four-rowed "nubbins" 

 surrounding a central well-developed 

 twelve-rowed ear. 



3. The central spike develops pistil- 

 late flowers much more readily than the 

 lateral ones of the tassel. The central 



spike has the greater number of rows of spikelets. 



4. He has observed the development of pistillate flowers 

 from staminate ones. This development is as follows: 



Fig. 6q. — Longitudinal 

 section of staminate 

 spikelet of Country Gen- 

 tleman sweet corn. X 1 5- 

 G, glume; Pa, palet; An, 

 position of one of the 

 lateral anthers; i, lem- 

 ma; A, dorsal anther. 

 P, rudimentary pistil; J, 

 joint of rachilla. (After 

 Weatkerwax.) 



