抄録
The somatic number of chromosomes in Chelidonium majus is determined to be 10 in root-tip cells. In the somatic nuclear plates the spindle fibre insertion is median in four chromosomes out of the ten and appears to be terminal in the remaining six.
In pollen mother cells, all of the univalent chromosomes, instead of pairing usually shown in late prophase of the first meiotic division, are found attached end-to-end with one another by thin threads to form a closed circle. At diakinesis one nucleolus connects at several regions to the chromosomes, the number of which is commonly six. It is recognized from the relations between nucleolus and chromosomes that there exists some number, possibly six, of satellite or nucleolar chromosomes.
The chromosomes linked together are arranged in the equatorial plane so as to present a zigzag appearance in side view. The mode of disjoining of the chromosomes is, generally speaking, regular, put it into other words the contiguous chromosomes pass to the opposite poles and the alternate ones to the same pole, the number of chromosomes in the daughter nuclei being generally five. In a few cases the numerical distribution is abnormal (cf. Table 1). Not infrequently at anaphase it happens that some of the unit chromosomes lag behind on the equatorial plane, being divided longitudinally.
From the aberration in the meiotic divisions, it is as a natural consequence that there exists in some extents abortive pollen grains and empty seeds. In facts, 68.97% of abortive pollen grains and 71.88% of empty seeds are found (Table 2, 3).
