收藏本站
收藏 | 投稿 | 手机打开
二维码
手机客户端打开本文

THE DIFFERENTIATION OF CHROMATIC AND ACHROMA-TIC SEGMENTS OF THE DEVELOPING SPERM-NUCLEUS OF SOME GRASSHOPPERS AS INDUCED BY ACIDS

【摘要】:正 1. A detailed study of the nucleus of a grasshopper, Acrida sp., duringthe transformation of spermatid into sperm has been carefully followed bythe Bouin-hematoxylin technic, but no. indication of segmentation of thesperm-nucleus in any stage of development has been observed.2. In smear preparations, all acetic stains will cause the sperm-nucleusof Acrida sp. differentially colored, producing chromatic and achromaticregions which are alternately and serially arranged, so as to render the wholenucleus regularly segmented.3. The phenomenon of segmentation is induced by acetic acid and notby the stain contained. Approximately 20% strength of acetic acid is theminimal concentration for the induction. Nitric and hydrochloric acids(and possibly all other inorganic and organic acids) induce the samephenomenon. Thus there exists a definite relationship between hydrogenion concentration and the phenomenon of segmentation.4. Increasing acetic acid strength in ordinary fixing mixtures will notproduce this expected phenomenon, since the other ingredients containedin the fixing mixture may counteract the action of acetic acid.5. For smear films, the writer found that pretreatment with vapor ofpure acetic acid followed by Bouin-hematoxylin yielded better results thanacetic stains. The present observations are based upon this technic and adetailed description is presented.6. The phenomenon of segmentation has nothing to do with temperatureor climate.7. More than sixteen species of local Orthoptera have been investieated,but only four species of grasshoppers are visibly segmented in their sperm-nuclei.8. The nature, formation, etc., of the chromatic and achromatic seg-ments ul question are skeptical in every restiect to the writer and are opento all for discussion. Anyhow, for the time being, it is safer to infer thatthe constitution of the sperm-nucleus is not homogeneous, a view in contradic- tion to the common conception that the sperm-nucleus is a compact mass ofchromatin. In addition to this, the dynamic aspect of the nucleus duringspermiogenesis must not be overlooked.9. From experimental point of view, at least, the phenomenon ofsegmentation of the sperm-nucleus as induced by acids can not be regardedas an artifact.

知网文化
 快捷付款方式  订购知网充值卡  订购热线  帮助中心
  • 400-819-9993
  • 010-62982499
  • 010-62783978