1．本邦産 Draparnaldia 属の２種　D. glomerata（VAUCH.）AGARDH および D. plumosa （VAUCH.）AGARDH と査定され得る材料を中心に，その形質の再吟味の結果，a）tascicules を構成する細胞数と総分枝回数の比および fascicules の発生の諸段階における相関傾向，ならびに　b）分枝の角度において，明かにこれら集団間に不連続形質としての有意差を認めることができる。
2．H. S. FOREST（1956）による glomerata-acuta-plumosa series を同一の種集団としてD. mutabilis（ROTH）BORY に整理統合しようとする提案に対しては，少くとも D. glomerata と D. plumosa は，別系列の独立した種集団として考えるのが，妥当であるとの結論に致った。

Several morphological trends of two species of Japanese Draparnaldia (D. glomerata and D. plumosa) are described, and a consideration for these phenomena has been given.
The variation of outline of fascicules, the branchlet bundles, is related to both the variation of the growth pattern of fascicules and the variation of the values of branching angles.
The interspecific discontinuous phenomenon found in the correlation pattern between the number of branching and the number of cells in each of the same fascicules of Japanese materials of D. glomerata and D. plumosa can be recognized. It is also observed that there is more remarkable discontinuity of the mode of variance of branching angles found in these different specific population.
Although, FOREST newly combined the several species of Draparnaldia, and also gave some emendation of specific characteristics of D. mutabilis (ROTH) BORY with a relation of the so-called "plumosa-acuta-glomerata" series of Draparnaldia in 1956, but remarkable significance of justification is recognized for dividing the presented series at several above mentioned morphological trends into separate specific populations at least D. glomerata (VAUCH.) AG. and D. plumosa (VAUCH.) AG.