A Botanical and Economic Study. 79 



and to send off numerous offshoots from the base. These 

 suckers grew as rapidly as the main stem, so that the plants, 

 which had been placed fortunately some feet apart, had the 

 appearance of two hills, one of the two having nine and the 

 other twelve stalks ascending from a common base." ' 



The production of suckers on annual plants in the north, 

 was probably a perennial habit in a more southern latitude, 

 so that in the semi-tropics the non-sexual development of 

 suckers was the ordinary method of propagation, the vigor 

 of the stock being rejuvenated by an occasional distribution 

 of seed by birds. 



BIBLIOGRAPHY. 



1. Asc/ierson, Ueber Euchlcena Mexicana, Schrad. Verhand. des Bot. 



Ver. Prov. Brand., 1875-76. 



2. Ascherson, Die botanische Yerwandschaft des Mais. Magyar. 



Novent. Lapok. Klaus., 1877, 19. Unger's Bot. 

 Zeitschr., 1877, No. 2. 



3. Ascherson, Bemerkungen iiber astigen Maiskolben. Sitz. d. Prov. 



Brand., xxi, 133. 



4. Reibisch, Ueber Maiskolben mehrfach entwickelt. Isis, 1875, 29. 



B. Histology. 



Maize is easily grown in all its stages, and it serves, there- 

 fore, as a type specimen with which other monocotyledons 

 can be compared. A complete histological description is 

 desirable. 



Root. — Janczewski, in his classification of angiospermous 

 roots, places the root of Zea in his second category defined 

 by the general tissue differentiation : " Sharply .marked 

 plerome cylinder and calyptrogen layer. Between the two, 

 at the apex of the punctum vegetationis, is an initial group 

 only one layer of cells thick, which splits immediately behind 

 the apex into periblem and dermatogen (i.e., cortex and 

 epidermis)." Most monocotyledons which have been inves- 

 tigated agree in this." A longitudinal section of the root 

 apex shows the following arrangement of tissues. The root 



1 Watson, Proc. Amer. Acad. Arts and Sci., xxvi, 158. 

 - De Bary, Comparative Anatomy, 10, Fig. 3. 



