新疆晚三叠世哈萨克虫动物群的进一步研究

新疆上三叠统黄山街组的哈萨克虫是一种已经绝灭了的淡水甲壳类，它与背甲目的淡水鲎虫是形态相似、关系密切、平行演化的两个枝系，但地质和地理分布远比后者短和局限，在划分和对比有关陆相地层上十分有意义。过去国内外学者曾对它进行过多次研究，但对化石本身一些结构构造和形态功能的了解还不十分清楚，甚或有错误。本文所研究的材料采自吐鲁番、准噶尔和塔里木盆地，270块标本上有400多个体，近半数保存有软体印模，有些标本连胸肢上透明的扇叶的轮廓也由刚毛的痕模压印了出来，有些标本上还保存有卵粒、食物团、才由肛门排出的粪便以及刚刚孵化出来的幼仔等，精美绝伦，堪称化石矿珍藏。通过对这些材料的研究，发现哈萨克虫有一对远远分开的眼睛长在唇瓣后侧前额的外缘，背器官下方的圆形凸起不是“一双愈合的复眼”，而与颚间片上的构造有关；除第二触角外还有第一触角，比前者略短；11对胸肢的最后两对稍有变化，其前端的3个内肢退化成2个，修正了过去对每个胸肢结构构造认识上的错误，找到了鳃副叶与扇叶的正确位置。记述了淡水鲎虫与哈萨克虫的区别，阐明了后者的生活习性，并对其个体发育、筋肉系统、血液与脱氧的关系、生存古环境等方面的问题进行了讨论和探索     

Variation in Quantitative Requirements for Na for Transport of Metabolizable Compounds by the Marine Bacteria Alteromonas haloplanktis 214 and Vibrio fischeri

The rates of uptake by Alteromonas haloplanktis of 19 metabolizable compounds and by V. fischeri of 16 of 17 metabolizable compounds were negligible in the absence of added alkali-metal cations but rapid in the presence of Na. Only d-glucose uptake by V. fischeri occurred at a reasonable rate in the absence of alkali-metal cations, although the rate was further increased by added Na, K, or Li. Quantitative requirements for Na for the uptake of 11 metabolites by A. haloplanktis and of 6 metabolites by V. fischeri and the characteristics of the Na response at constant osmotic pressure varied with each metabolite and were different from the Na effects on the energy sources used. Li stimulated transport of some metabolites in the presence of suboptimal Na concentrations and for a few replaced Na for transport but functioned less effectively. K had a small capacity to stimulate lysine transport. The rate of transport of most of the compounds increased to a maximum at 50 to 300 mM Na, depending on the metabolite, and then decreased as the Na concentration was further increased. For a few metabolites, the rate of transport continued to increase in a biphasic manner as the Na concentration was increased to 500 mM. Concentrations of choline chloride equimolar to inhibitory concentrations of NaCl were either not inhibitory or appreciably less inhibitory than those of NaCl. All metabolites examined accumulated inside the cells against a gradient of unchanged metabolite in the presence of Na, even though some were very rapidly metabolized. The transport of l-alanine, succinate, and d-galactose into A. haloplanktis and of l-alanine and succinate into V. fischeri was inhibited essentially completely by the uncoupler 3,5,3',4'-tetrachlorosalicylanilide. Glucose uptake by V. fischeri was inhibited partially by 3,5,3',4'-tetrachlorosalicylanilide and also by arsenate and iodoacetate.