The result shows that sperm ultrastructure , spermatogenesis , oogenesis and mature oocyte structure all have the characteristics unique to palaemon modestus . therefore , my researches ca n ' t only enrich the contents of reproductive biology in crustacean but also provide basic references for pond culture in palaemon modestus 结果显示：秀丽白虾精子结构、精子发生过程、卵子发生过程、成熟卵结构均有种的特属性，从而本研究不仅可以丰富甲壳动物生殖生物学内容，同时也可为秀丽白虾人工养殖提供基础资料。
In the past several decades , all kinds of research work have been carried out on the genetic resources of genus malus species . therefore , much progress has been made concerning the studies of the number of species , geographical distribution , morphology , classification , cytology , cell biology , reproductive biology and resistance characters to various environmental stresses 在过去的几十年中，我国的苹果资源研究工作者对苹果属植物的种类、数量、分布、形态学、系统学、孢粉学、细胞学、生殖生物学和抗逆境生物学特性等众多方面开展了广泛、系统和深入细致的研究，取得了许多重要成果，但也存在明显不足。
