372 BOTANICAL GAZETTE [November 



another, but at other times more or less parallel, resulting in differ- 

 ent arrangements of megaspores (pi. figs. 23-26). The micro- 

 pylar megaspores degenerate in connection with the maturation of 

 the large innermost one in forming the embryo sac (pi. fig. 27). 

 In my material I observed all of the megaspores disorganizing 

 (fig. n), and it is evident that this disorganization of the megaspore 

 which ordinarily gives rise to the embryo sac is one reason for seed- 

 less fruit. In such a country as Japan, where many different kinds 

 of persimmons are cultivated together, the difficulty of pollination 

 is out of the question. 



Summary 



1. Diospyros Kaki is not a dioecious plant, but a monoecious 

 one whose staminate flowers are disappearing under cultivation. 



2. The monoecious habit might have been derived from a con- 

 dition of perfect flowers; therefore this habit is not a primitive 

 character in this species. 



3. Perfect flowers do not indicate the primitive character of the 

 variety in which they occur ; they appear among other varieties only 

 through restoration of lost parts. 



4. The primitive character of Ebenaceae among Sympetalae is 

 indicated by the spiral arrangement of petals; the stamen situation, 

 although the number of stamens is not definite; and the two 

 integuments. 



5. Megaspore formation is also of a primitive character, and 

 suggests, along with other characters of the family, that it may 

 have some relation to the Myrtiflorae. 



6. There is no parietal tissue in the microsporangium, which 

 indicates that Ebenaceae come from some higher family of Archi- 

 chlamydeae, because in the lower families parietal tissue usually 

 occurs in the megasporangium. 



7. Embryo sac formation occurs in the usual way, and in general 

 furnishes no evidence for the evolution of dicotyledons. It is true 

 in general, of course, that the gametophytes of angiosperms are 

 of less value for evidence concerning evolution than the sporo- 

 phytes. 



