178 ORGANISMS ILLUSTRATING BIOLOGICAL PRINCIPLES 



former gives rise to the young plant, the latter to its food supply, the 

 endosperm. The transfer of pollen in flowers of the same species 

 may result in the fertilization of the egg and subsequent growth of 



Division I 



Thallopbyta 



algcxe. "^ 



Division I 



Bryophyta 



Division BE Tr-ccchsopViyta.- vasculcti- T=lcL"ts 



subdivision A*B;vc ^abdVvi/ion D PteropsicCcc 



ferns ^^rnnospe4*ms angiospcrrrjs 



primiuve plants 



Lvcopsida ,Sl*enopJic£a 



^ener-cction 



Diagram showing relation of sporophyte and gametophyte generations in the 



plant kingdom, 



the plant body (sporophyte generation). The evolution of sporo- 

 phytic and gametophytic generations in the plant kingdom is shown 

 in the above chart. 



SUGGESTED READINGS 



Coulter, J. M., Barnes, C. R., and Cowles, H. C., A Textbook of Botany, 



Vol. I, American Book Co., 1930. 



This text gives an excellent foundation for the understanding of sexu- 

 ality in plants. 

 Gager, C. S., General Botany, P. Blakiston's Son & Co., 1926. 



A general botany which gives much information on economic questions, 



as well as sex development in simple plants. 

 Robbins, W. J., and Rickett, H. W., Botamj, D. Van Nostrand Co., 1929. 



Chs. XV-XXIV. 



Excellent diagrams help in the understanding of the development of sex. 

 Sinnott, E. W., Botany, Principles and Problems, 3rd ed., McGraw-Hill Book 



Company, 1935. Chs. XI and XIV-XXIII. 



A thoroughly up-to-date treatment of the subject. 

 Wilson, C. L., and Haber, J. N., Plant Life, Henry Holt & Co., 1935. 



An interesting and well-written elementary text. 



I 



