A Botanical and Economic Study. jj 



interesting similarities. The female spikes in maize, in all 

 probability, are fasciated into a continuous cob, and when 

 ripe the ear has a tendency to break into joints or pieces. 

 The spikes in Tripsacum are axillary and terminal, separating 

 spontaneously at maturity into joints. The pistillate spike- 

 lets, two-flowered, with inner flower fertile, the outer flower 

 abortive, are imbedded in an oblong joint of the thickened 

 rhachis, occupying a boat-shaped recess, which is closed by the 

 cartilaginous outer glume. Zca has two spikelets, spikelets 

 two-flowered with inner flower fertile, the outer aborted, 

 placed in a cucullate depression of a fleshy cob. It seems 

 that the fleshy cob has been formed by the union of several 

 distinct spikes ; this conclusion is strengthened on compar- 

 ing Zea with Euchlcena and Tripsacum, for in the two latter 

 genera the joints are trapezoids, and easily disarticulated, 

 with the fruit set in a cartilaginous capsule, forming a 

 false fruit. A study of depauperate ears supports this 

 view. A bifurcation of the tip frequently occurs, when 

 the rhachis is prolonged into two axes. The tissues some- 

 times separate sufficiently to show the different spikes which 

 compose the fleshy cob. The arrangement of the grains 

 corresponds to the separate spikes of the consolidated cob. 

 These structural and teratological arrangements point to the 

 probable union of several spikes into a thick, fleshy axis, with 

 grains on the circumference, each paired row limited at the 

 side by a long, shallow furrow, a row corresponding to a single 

 spike of Euchlcena or Tripsacum. 



The branch with alternate arrangement of ears (Fig. 9, 

 Plate XV), seems to be the more primitive, for cultivated 

 forms with one ear enormously developed have frequently 

 two or three ears placed in the axils of husks enclosing the 

 larger fertile ear. 1 One ear, in the cultivation of corn for 

 centuries, has enlarged at the expense of the others, furnish- 

 ing another illustration of the law of compensation in growth. 2 



Professor Duges found this corn called by the natives " maiz 



1 Cornell Agric. Exp. Stat., Bui. 49. Dec, 1S92, p. 333 See Bibliography, end 

 Section A. 



■ St.-Hilaire called it "correlation of growth." 



