Abstract
This paper deals with the relationship between the length of the style and the shape of the idioblast. The results are summarized as follows:
(1) In general, the styles of M. bombycis K. are long and those of M. alba L. and M. multicaulis P. are short or lacking, but they are variable very much, varying from 0 to 2.35mm. in M. bimbycis K., from 0 to 0.74mm. in M. alba L. and from 0 to 0.88mm. in M. multicaulis P.
(2) Generally, the idioblasts of Type C are dominant in number in M. bombycis K. and those of Type B are dominant in number in M. alba L. and M. multicaulis P.
(3) Even though muberry races belong to M. bombycis K., if the styles of them are short or lacking, their idioblasts show Type B in many races. (In the present examination 63% of races tested showed the idioblasts of Type B.)
(4) Among the races of M. alba L., the group of Ichibei races and the group of Takowase races showed the idioblasts of Type C. These facts suggest that there are some special genetical relationship among those races, which belong to the same group.
(5) Almost all races of the long style group of M. bombycis K. showed the idioblasts of Type C; almost all races of the short (or no) style group of M. alba L. and all races of the short (or no) style group of M. multicaulis P. showed the idioblasts of Type B. These facts show that there is a close relationship between the two features, the length of the style and the shape of the idioblast.
(6) From the facts mentioned above, it is assumed that mulberry races, which belong to M. bombycis K. but have the short (or no) styles and the idioblasts of Type B, or mulberry races, which belong to M. alba L. or M. multicaulis P. but have the medium styles and the idioblasts of Type C will be the hybrid ones between two or three species. However, it needs further research to confirm this hypothesis
(7) As pointed out by many botanists, the length of the style is one of the most useful features for classification of mulberry trees, at the same time, it is safe to say that the shape of the idioblast is also a useful feature for the purpose.
