Volume 15, Issue 3
March 1942, pages 133-166
pp 133-147 March 1942
A brief review of the three important species of theDurra group,viz.,S. durra, S. cernuum andS. subglabrescens, with special reference to the Indian and particularly to Madras varieties, is given.S. rigidum, also included in this group but which does not fit in with this, is omitted. Detailed descriptions and distinguishing characteristics of the varieties of these three species cultivated in the Madras Presidency are provided. A short review of the important characters met with in this group has been added at the end with special reference to panicle shape and glume wrinkling. Figs. 1–6 illustrate the different types of panicles, panicle branches, spikelets, grain shapes, glume wrinkling and node hairiness in the different species.
pp 148-152 March 1942
pp 153-157 March 1942
The inflorescence axis ofRumex patientia has bicollateral bundles whose internal phloems give rise to obcollateral, ob-bicollateral and amphivasal bundles. Sometimes two or three internal bundles lie in association with a single outer bundle. It is concluded that the presence of such bundles is an advanced character. Farther, the condition inRheum, where the internal bundles lie detached from the outer ones, is easily derived from that inRumex.
pp 158-166 March 1942
A reinvestigation of the embryo-sac ofEuphorbia heterophylla shows that the development is not of theAdoxa- type as reported by Sanchez (1938) but of theNormal- type. The megaspore-mother cell gives rise to a tetrad of megaspores of which the chalazal cell functions to produce a normal 8-nucleate embryo-sac.
It is pointed out that as a rule vacuolation and polarity are not seen in embryo-sacs until after the reduction divisions are over. They form such reliable guides that all cases, where the reported observations are not in accordance with the above, deserve a fresh study.