THE spiders are distinguished by their sex chromosome mechanism. Painter (i 914, partially in conformation of earlier work by Wallace and others) has definitely shown that the males of 13 species, each from another family, have two X's which pass to the same pole in the first meiotic division, thus leading to two kinds of sperms with either two X's or none. Hard (1939) described another case of this type. Only recently an exception was discovered by Revell (1947) in Tegenaria. He found the usual two X's in one species but three X's in two other species. In all these cases the female must have twice the number of X's. This was first confirmed by Revell. But a comparative study of meiosis in males and females had never been undertaken. The main cytological problem in spiders—by what means the joint segregation of the X's is secured—was solved by Revell in Tegenaria, but it had yet to be seen whether the special mechanism in this genus is present in all spiders. In fact, it is not, so this question was still open. The material at hand, males and females, proved favourable not only to deal with these tasks but to gain some information concerning more general problems such as heterochromasy, nucleic acid metabolism and spiralisation. Furthermore, the question of the origin of the multiple X-mechanism had to be raised and that cannot be treated adequately without genetical considerations which have been rather neglected so far. The present study was begun in 1934 at the Kaiser Wilhelm Institut fur Biologie in Dahiem but fortunately not finished, since, when this was done in Merton, the conditions in Tegenaria could be taken in full account. I am obliged to Dr Revell for much information on this genus and for letting me see his paper before it went to press.

中文翻译：

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蜘蛛蛛的 X 分离和异色症

蜘蛛的区别在于它们的性染色体机制。Painter（i 914，部分符合 Wallace 和其他人的早期作品）明确表明，13 个物种的雄性，每个来自另一个科，在第一次减数分裂中都有两个 X，它们传递到同一极，从而导致两个带有两个 X 或没有 X 的各种精子。Hard (1939) 描述了这种类型的另一个案例。直到最近，Revell (1947) 在 Tegenaria 发现了一个例外。他在一个物种中发现了通常的两个 X，但在另外两个物种中发现了三个 X。在所有这些情况下，女性必须拥有两倍于 X 的数量。这首先得到了Revell的证实。但从未进行过雄性和雌性减数分裂的比较研究。蜘蛛的主要细胞学问题——X' 的联合分离是什么意思？s 是安全的——由 Revell 在 Tegenaria 中解决，但该属的特殊机制是否存在于所有蜘蛛中还有待观察。事实上，事实并非如此，所以这个问题仍然是开放的。手头的材料，男性和女性，被证明不仅有利于处理这些任务，而且有利于获得一些关于更普遍问题的信息，如异色症、核酸代谢和螺旋化。此外，必须提出多重 X 机制起源的问题，如果没有迄今为止被忽视的遗传因素，就无法充分处理这一问题。本研究于 1934 年在 Dahiem 的 Kaiser Wilhelm Institut 毛皮生物学研究所开始，但幸运的是尚未完成，因为在 Merton 进行时，可以充分考虑 Tegenaria 的条件。