1915] VYASUI—DIOSPYROS KAKI 363 
were observed, they were dioecious, and bore only perfect flowers. 
One possible exception has been found recently.” In D. Kaki, on 
the other hand, there are many such exceptions, as follows. 
1. In some varieties only the pistillate flowers occur in good 
condition, while all the staminate and some of the pistillate flowers 
are imperfectly developed. 
2. In other varieties (gosho, egosho, yamagaki, jenjimaru) 
both kinds of flowers are always well developed. 
3. A tree in Mr. Yasr’s garden in Tokyo (no. 1 of my 
material) has the same type of fruit as in some of the varieties in 
group 1, but has pistillate, staminate, and perfect flowers, and 
produces also two types of fruit from the two kinds of flowers. 
4. No tree has been discovered by the writer on which only 
staminate flowers occur. 
5. Some varieties have pistillate flowers only, when the trees are 
young, but as they become older or weaker (on account of poor 
nutrition or transplanting) they begin to produce staminate flowers 
also (hyakume-gaki). 
6. Some trees show an section of fruiting and non-fruiting 
years, which means that during one year they produce many pistil- 
late flowers and many fruits, while during another year they pro- 
duce a few pistillate flowers and abundant staminate flowers. 
Under the latter conditions they bear very little fruit, or no fruit 
at all. 
It may be added, in reference to the fourth condition referred 
to, that in Japan the staminate trees are being continually destroyed 
unconsciously, because the better varieties are produced always by 
grafting, and therefore many seedlings of staminate plants are 
destroyed, and pistillate plants take their place. The foregoing 
data gave me the suggestion that D. Kaki is naturally a monoecious 
plant (fig. 1), and that it is in process of losing this character, pro- 
ducing staminate flowers under cultivation. 
I have selected five different varieties from one hundred or more 
for this study, as follows. 
No. 1.—I am not certain of the name of this variety, but it 
resembles ‘‘yemon,”’ which is an astringent, flat type. The differ- 
ence is that yemon has no staminate flowers at the Okitsu 
