物作玉术叶的研究················…….’.二·,.’.’.’.’...,’....··..···········,··························……试刊(17)套种及夏播玉米的雌穗分化过程观察研究····················· Study on the jade leaves of jade leaves ······... .. ···················································································································································· Study on Ear Spike Differentiation of Sowing Corn ·······································································