SEX CHARACTER IN PLANTS 249 



single females with double males, the doubles produced are herma- 

 phrodite males and sterile females. The female parent being single, 

 fertile females carrying the "double" character apparently do not 

 result, at least to the second generation (F. 2). There seems to be 

 some likelihood here of a clue to the nature of the double 10-weeks 

 stock, of which, also, the double flowers are presumably sterile 

 females. Meanwhile, some of these new flowers, mere by-products 

 on the line of investigation, are singularly desirable flowers. 



It is not possible here, even in outline, to indicate the trend of 

 many of the experiments which are being conducted, the conclu- 

 sions from most of which are at present most tentative. In 

 working with begonias, after some years of experiment, the 

 curious discovery was made, to the surprise of the discoverers 

 themselves, that the ordinary exhibition type of double begonia is 

 in many cases, if not in all, female. Some of the specimens carry 

 ovules free on the petals. The discovery has necessitated the 

 wiping out of the results of some four or five years of investiga- 

 tions which had been carried on on the supposition, as is the 

 current belief, that the flowers were male. 



Some very interesting suggestions are made, again, by the 

 results of experiments with the varieties of the liliaceous plant 

 CJdorojjJiytuvi, which has leaves variegated in longitudinal stripes 

 of yellow and green. From forms of which the middle of the leaf 

 is yellow and the edges green it is found that the seedlings are 

 yellow. Where the colours are reversed — green in the middle 

 and yellow at the edges — the seedlings are green. That is to say, 

 that the seedlings appear to carry the characteristics of the stem 

 and midrib and not of the outer portion of the leaf. If this is 

 constant, it would seem to throw a ray of light on the question of 

 what portion of the soma or body of an organism it is from which 

 the germ derives its character ; a matter which may have an 

 obvious bearing on inheritance in many things besides plants. 



An exhaustive series of experiments has been made in coloura- 

 tion, using the common snapdragon or Antirrhmum, some of the 

 results of which have been already embodied in scientific papers 

 by the investigators. Briefly it has been found that all the 

 combinations and variations of colouring in Antirrhinums are 

 derived from four pigments — namely, ivory, yellow, red, and 

 magenta. All of these have been isolated and obtained in a pure 

 form, and the chemical identification of them is now possible. 

 The first-named two pigments have been identified with apigenin 

 and luteolin respectively. 



This chemical interpretation of Mendelian factors may obviously 

 be a matter of far-reaching importance. We can hardly imagine 

 the possibility of tracing through the germ the principle which 

 makes for longness or shortness in pea plants (as in Mendel's 

 famous experiments), or which produces the rose comb or single 

 comb in fowls ; but we seem to be getting within reach of some- 

 thing more tractable when we deal with a common colouring 

 matter of known constitution. The equation begins to be not all 

 unknown quantities. 



