iqiq] STOUT—IXTERSEXES 123 



of variation is to be seen bver a wide geographical area. Un- 

 doubtedly many of the plants classed as intermediate gynomo- 

 noecious. especially by Correns, present a range of variations 

 quite identical to those here described. 



The wide geographical range of this species, and especially its 

 recent rapid spread in America, give opportunity to observe to 

 what extent there is geographic distribution of races possessing 

 distinctive differences in sex heteromorphism. 



Discussion 



The term intersexuality, as especially applied by Goldschmidt 

 to conditions of sex in Lymantria dispar, can with equal adequacy be 

 appHed to such sex variations as are evident in Plantago lanceolata. 



It must be recognized that the significance of such variations 

 is to be sought in the conception that there may be different 

 degrees in the expression of maleness and femaleness. Cases of 

 intersexuality afford material for the study of stages and degrees 

 of sexuality and sex determination. 



The observations reported for P. lanceolata refer almost 

 entirely to maleness. The variations in development of the 

 stamens, with their anthers and contents, are easily and directly 

 to be observed. E\'idences of marked variations in the develop- 

 ment and functioning of the pistils are also in evidence, and further 

 studies of femaleness are in progress. 



It is very evident that there is a wide range of variation in 

 the degree in which maleness is expressed. Measured by the 

 amount of sporogenous tissue, there is every degree of sexual 

 development between the highest grade seen and complete steril- 

 ity. The size of the stamen as a whole and the size and shape 

 of its various parts exhibit a series from the normal to extremely 

 rudimentary structures. There are two forms in which this 

 decrease in maleness is expressed. In one the stamens are greatly 

 reduced in size; in the other they become foliose. The foliose 

 character is seen first in the slight enlargements of the sterile 

 tissue at the apex of the anther, as shown in figs. 19 and 29. 



It is to be recognized that the impotence of one or the other 

 of the sex organs involved in intersexuality is to be distinguished 



