72 WRIGHT : THE GENUS DTOSPYROS 



It must here be stated that the female flowers of I), acuta, 

 D. sylvatica, and D. Ebenum may occur in the solitary or 

 grouped condition on the same tree. It now remains for us 

 to study the relationships between the parts of a solitary 

 female flower and the members of a female inflorescence. 



Development of the Female Flowers in D. Gardneri, D. 

 Em bryopteris, and others. In D. Gardneri the pubescent 

 flower bud arises in the axil of a new or old foliage leaf. 

 The peduncle is very short and rarely exceeds 0*4 cm. in 

 length, but very soon two small leaves appear at right angles 

 to the antero-posterior axis. In addition to these a third leaf 

 may appear between the normal foliage leaf and the anterior 

 side of the flower, and this may be followed by a fourth on 

 the opposite side between the axis and the posterior side of 

 the flower. Under ordinary circumstances, and even if the 

 flowers be cut away so as not to greatly disturb surrounding 

 organs, no development takes place in either of the bracts 

 numbered 1, 2, 3, and 4. If, however, we now study the 

 development of the female inflorescence in D. Ernbrypperis, 

 we find exactly the same sequence of events, but in addition 

 a flower bud appears in the axil of each of the small leaves 

 on the primary peduncle (pi. IX., figs. 7-10). Similarly 

 with the female inflorescences of other species. It is further 

 to be noted that when the female inflorescence forms a 

 sessile cluster the appearance of each flower is always pre- 

 ceded by that of the small leaf, and in many of them a 

 considerable amount of abortion occurs. 



Often in D. Thwaitesii there is a solitary female flower 

 surrounded at the base by an involucre of bracts, abortion 

 having occurred in the axil of the lower bracts. We may 

 therefore arrange the female flower systems in one series to 

 show that the solitary flower arrangement is probably derived 

 from the cymose inflorescence by abortion in the axil of the 

 lower bracts. This is the most likely course of evolution, 

 since the lateral flowers in the inflorescence of D. Embry- 

 opteris often drop before they reach maturity in consequence 

 of the pressure exerted by the quickly growing median flower. 



