On the Connection between the Nucleouls and the Spireme in Hordeum.

[摘要] 1. The material used in this investigation is the pollen mother cells of Hordeum sativum, Jess. fixed in BOUIN, s solution. Sections wore cut at a thickness of 7 or 10 micra and stained in HEIDENHAIN's iron-alum-haematoxylin. 2. The connection between the nucleolus and the spireme in the pollen mother cell has been observed by CLELAND in Oenothera (1922 and 1924), by LATTER in Lathyrus (1926) and by the Writer in certain cultivated plants (1929). But in all these cases the connection was observed only in the prophase of the meiotic division. In this investigation, however it is found in Hordeum that the spireme is connected with the nucleolus not only in the prophase (Figs. 1 and 2) but also during the stages of interkinesis (Fig. 5) and second telophase (Fig. 9). But in the prophase as shown in Fig. 1 the spireme which is concentrated into a bundle connects with the uncleolus at only one point, its pole, while in the stages of interkinesis and second telophase, as will be seen in Figs. 5 and 9, the spireme is connected with the nucleolus at several points. 3. In the early strepsitene stage the spireme connected directly with the nucleolus is dark containing much chromatin (Fig. 2). This would indicate that during this stage a movement of chromatin occurs from the nucleolus to the connecting spireme to produce chromosomes. Such a movement of chromatin seems to take place also during the second prophase (Fig. 6). Therefore, all the result of this investigation seem to indicate that the nucleolus is the source of the chromatin of the chromosomes.

[学科分类] 农业科学（综合）