The effects of anterior and posterior selections on fission rate in pure lines of Paramecium caudatum

✍ Scribed by De Garis, Charles F.

• Publisher: John Wiley and Sons
• Year: 1928
• Tongue: English
• Weight: 604 KB
• Volume: 50
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1400500102

✦ Synopsis

It was the verdict of Maupas ('88) that among the Protozoa no morphological or physiological diff erences arise in the products of a given fission or in the continuous generations derived therefrom. Many differences may be found between races or lines of the same species, but within the single race, or 'pure line,' such differences as may arise are not heritable; hence the conclusion that selection for such differences has no effect within a pure line. R;luch work could be cited in support of this conclusion.

Jennings ('08) attempted to change the size of a race of Paramecium by selecting, on the one hand, large individuals, on the other hand, small ones, but his long continued efforts brought out no heritable change in the race. This work was repeated by Ackert ('16) with the same results. Jollos ( '13) 1