Anterior regeneration in the earthworm, Eisenia, in the certain absence of central nervous tissue at the wound region
✍ Scribed by Bailey, P. L.
- Publisher
- John Wiley and Sons
- Year
- 1939
- Tongue
- English
- Weight
- 644 KB
- Volume
- 80
- Category
- Article
- ISSN
- 0022-104X
No coin nor oath required. For personal study only.
✦ Synopsis
It has been demonstrated (Bailey, '30) that the earthworm (Eisenia foetida, Savigny) will not regenerate a tail if the vcntral nerve cord has previously been looped back from the region of amputation for a distance of several segments, thus leaving the wound region entirely without nervous elements and free from efferent impulses, o r other iiifluences originating in the central nervous system. Zhinkin ('36) confirms this conclusion for posterior regeneration in Rhynchelmis, although he points out that removal of the cord does not inhibit regeneration of the epithelium necessary for wound closure. Morgan ( '02) maintains that in anterior regeneration the nerve cord must be present a t the cut surface if a new head is to regenerate.
However, the experiments of Goldfarb ('09), Siegmund ( '28), Avel ( '30, '32), Kropp ( '33) and Crowell ( '37) seem to indicate that in anterior regeneration the formation of new regenerating tissue and the organization of this tissue into a new head may occur even when the cephalic ganglia and ventral nerve cord have been removed from several segments adjacent to an anterior wound region.
The experiments described in this paper were begun during the summers of 1931 and 1932 in an attempt to determine more 287