原卵

Oogonium develops into early oocyte in the ovary, and then the oocyte leaves the ovary for the coelomic fluid in the form of single cell or cell mass followed by the rapid separation of the group of oocytes into individual ones. Oocyte enters into the nephridium after its maturation. The rupture of germinal vesicle marks the oocyte maturation. Oocyte in the coelom does not have follicle membrane and vitelline membrane is formed and developed by the oocyte itself. Smaller oocyte (0μm in diameter) is round, and larger ones (≥60μm in diameter) is ovate. The short and long diameters of a morphologically mature oocyte are about 115—120μm and 140—145μm respectively, and the vitelline membrane is 7—9μm thick.

卵原细胞在卵巢中发育至早期卵母细胞时期单个或成团脱离卵巢入体腔液中，卵母细胞团细胞很快分离为单个细胞；卵母细胞在体腔液中发育成熟后进入肾管；生发泡破裂是卵母细胞成熟的标志；体腔中卵母细胞无滤泡膜，卵黄膜的形成与发育靠卵母细胞本身；卵径小于60μm的卵母细胞呈圆形，卵径大于60μm 的卵母细胞为卵圆形，形态上成熟的卵母细胞短径约115—120μm、长径约140—145μm、卵黄膜厚7—9μm。

The snail was found to have an indirect developmental type in the early development. The fertilized eggs were oval-shaped and discoidal cleavage. Embryonic development stages were divided into cleavage, blastula, gastrulae, trochophore, and intra-membrane veliger. Larval development stages included veliger, late veliger and crawling larvae metamorphosed to juvenile.

结果表明：黄口荔枝螺卵囊高度平均为7.33 mm，卵粒数量平均为165粒；黄口荔枝螺的早期发育属间接发生型，受精卵呈椭圆形，卵裂为盘状卵裂；在卵囊内，胚胎发育包括卵裂期、囊胚期、原肠胚、膜内担轮幼虫、膜内面盘幼虫；幼虫发育包括面盘幼虫、后期面盘幼虫和匍匐幼虫。

The results show that, with the maturity of the gonad, the undifferentiated germ cell divided and differentiated to smaller oogonium or spermatogonia, and the oogonium or spermatogonia transformed to oocyte and sperm undergoing a series of maturation process.

摘 要 通过观察栉江珧的未分化生殖细胞，精原细胞和卵原细胞，精母细胞和卵母细胞，精子和卵子的形态结构与分布状况及核仁在卵成熟过程中的变化，对栉江珧生殖细胞发生及成熟过程的有关问题进行了探讨。

According to the size and shape of oocyte, the morphology of nucleolus, the growth of yolk and the structure of follicle, oogenesis of H. d. supertexta can be divided into three stages as follows: oogonium, previtellogenic oocyte and vitellogenic oocyte. The ovary wall is composed of tunica adventitia and germinal epithelium which will produce oogonia and follicle cells. The follicle is the structure unit of ovary.

根据卵细胞的大小、形状，核仁的形态，卵黄颗粒的积累情况，滤泡的结构等，将九孔鲍卵子的发生分为卵原细胞、卵黄发生前的卵母细胞和卵黄发生期的卵母细胞3个时期；卵巢壁由外膜及内生殖上皮构成，生殖上皮分化产生卵原细胞和滤泡细胞；卵巢的结构单位是滤泡。

The oogenesis of P. esculenta can be divided into the following phases in morphological characteristics of oogonium and oocyte development: the proliferative phase of oogonium (0μm in diameter), the initial growth phase of oocyte (10—20μm in diameter), the grand growth phase-Ⅰof oocyte (20—60μm in diameter), the grand growth phase-II of oocyte (60μm×70μm to 120μm×145μm in size), the mature phase of oocyte, and the declining phase, showing a dynamic changes in oogenesis of P. esculenta .

以卵原细胞与卵母细胞发育的形态学特征为依据，将可口革囊星虫的卵子发生过程划分为：卵原细胞增殖期(卵径0μm)、卵母细胞小生长期(卵径10—20μm)、卵母细胞大生长期Ⅰ(卵径20—60μm)、卵母细胞大生长期Ⅱ[大小为(60μm×70μm)—(120μm×145μm)]、卵母细胞成熟期及退化期6 个阶段，反映了可口革囊星虫卵子发生过程的动态变化。

The spore germination and gametophyte development of 21 ferns are studied. It indicates that :① the development period of prothallium and young sporophyte of the same species is different due to seeding time of spores;② the optimal temperatures of spores germination and gametophyte development of 21 ferns are about 15 -24 ℃;③ the rate of spore germination of rare ferns is much lower than the ferns which occur large populations in nature;④ the treatment with GA 3 can accelerate the germination of the spores;⑤ the prothallium changes from large to small, green to yellow when young sporophyte comes out. The prothalliums of all 21 ferns die away after the appear of the 3rd leaf of sporophytes;⑥ shapes of the 1st and 2nd leaves of the young sporophyte are different from those emerged later;⑦ spores cultured in dark can not germinate;⑧ a prothallium can develop only one young sporophyte though it has many archegoniums, and the spore propagation with leaf mould substrate is an economical method.

摘 要：以腐叶土为培养基质，对 21 种蕨类植物进行了孢子萌发和原叶体发育的研究，结果表明：①不同时期播种的同种蕨类的孢子，发育出原叶体和幼孢子体所历经的时间长短不同；②孢子萌发和配子体生长发育的适宜温度约为 15 ～ 24 ℃；③稀有蕨类的孢子萌发率低，而在野外能形成较大种群的蕨类的孢子萌发率高；④用 GA 3 处理孢子可以促进萌发；⑤当原叶体上长出幼孢子体时，原叶体由大变小，由绿变黄， 21 种蕨类的原叶体都在幼孢子体上长出第 3 片叶时消失；⑥幼孢子体上长出的第 1 、 2 片叶在形态上与以后长出的叶不同；⑦孢子萌发需要光；⑧ 1 片原叶体尽管有多个颈卵器，但仅发育出 1 株幼孢子体；⑨利用腐叶土进行蕨类孢子繁殖是一种经济实用的繁殖方法。

Neurogenesis and development of the central nervous system in the embryo stage of swimming crabs, Portunus trituberculatus, were studied by the histological method.

应用组织学方法研究三疣梭子蟹胚胎期中枢神经系统的发生和发育，光学显微镜下镜检切片，在第二期卵内无节幼体阶段开始观察到脑；第二期卵内状幼体阶段，前脑由视神经层、侧原脑和中央原脑组成，与位于食道两侧的中脑和后脑形成完整的脑。

The results were as follows: nanos 1 mRNA uniformly dispersed throughout the cytoplasm of oocytes at all stages. Strong expression of nanos1 mRNA was observed in oogonia and stageⅠ、Ⅱ oocytes, but the signal became weaker in later stage oocytes.

结果表明：在斑马鱼卵子发生中，nanos1 mRNA均匀分布于卵原细胞和各时期卵母细胞的胞质中；在卵原细胞和Ⅰ、Ⅱ期卵母细胞中，nanos1 mRNA的杂交信号十分强烈，而较晚期卵母细胞中信号明显减弱。

Stage I of both male and female stone flounder appears only once in all its life, and the germ cells are comprised by spermatogonia or oogonia. The gonad from Mar to Aug keeps at stage II. The gonad index of testis at this stage is 0.037%, and the amount of spermatogonia is increased quickly. There is some linear germ plasm in the cytoplasm of spermatogina. In ovary at this stage it is mostly composed by oocyte of phase 2 which the character is the appearance of yolk nucleus, and no zona radiate in membrane. The mean GI of ovary is 1.95%. From Sep to Oct gonad is at stage III which testis is composed by lots of spermatogina and few spermatocytes, and the mean GI of testis at this stage is 0.086%. In ovary the ooctyes at phase 3 are in dominate position, the yolk nucleus disappear. And the GI of this stage is 3.35%. Both testis and ovary are at stage IV in Nov. hi testis the germ cells are in spermiogenesis, and the mean GI is 0.93%. hi ovary the oocytes are mostly at phase 4, which are filled in the cytoplasm with vitellin granule, and the zona radiate in membrane begins to formation. Nucleus moves to one side of the oocyte gradually. The mean GI of ovary at this stage is 9.37%.

在每年的3月-8月期间性腺处于Ⅱ期，此期精巢中精原细胞明显增多，胞质局部可见有线状的生殖质存在，平均成熟系数为0.037％；卵巢中以2时相卵母细胞为主，可见细胞质中出现强嗜碱性的卵黄核，细胞外由一层滤泡细胞包围，但尚无放射带，平均成熟系数为1.95％。9月-10月期间性腺处于Ⅲ期，此期精巢中仍有大量精原细胞，同时可见部分精母细胞，平均成熟系数为0.086％；卵巢中以3时石鲜孟加限加$玩印面n洲匆s性腺发生、分化及发育的周年变化相卵母细胞为主，细胞质中的卵黄核己消失，平均成熟系数为3.35%。11月性腺处于IV期，此期精巢内精细胞正处于不同的形成过程中，平均成熟系数为0.93%；卵巢中以4时相卵母细胞为主，胞质中充满染成桔红色的卵黄颗粒。

Also, the intensity of immuno-positive reactions to them enhance with the development of the gonads.

免疫组织化学法也显示卵原细胞、卵母细胞、精原细胞、精母细胞和精子细胞存在睾酮和17β-雌二醇的免疫阳性物质，而且睾酮和17β-雌二醇的免疫反应强度也是随着性腺发育成熟而增强。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。