REGENERATION IN ANNELIDS
HENRIETTE HERLANT-MEEWIS
Laboratoire de Zoologie: Histologie Comparée,
Université de Bruxelles, Belgium
I. Introduction
155
II. Blastema Formation
156
A. Regenerative Elements
156
B. Biochemical Factors
172
C. Role of the Nervous System
174
III. Differentiation of the Regeneration Bud
187
A. Caudal Regeneration
187
B. Cephalic Regeneration
189
IV. Importance of the Nervous System in Morphogenesis
194
V. Endocrine Role of the Nervous System
196
A. Experimental Facts
197
B. Histophysiological Bases
203
VI. General Conclusions
209
References
211
I. Introduction
Annelids provide excellent material for the study of regeneration.
Their relatively simple structure facilitates analysis of the regenerative
processes and, in addition, they also have a very high capacity for
regeneration.
Since the end of the last century, numerous workers have dealt with
the many aspects of these phenomena as revealed in experimental regeneration as well as in the varied modes of asexual reproduction.
There are many up-to-date and comprehensive surveys of the work
dealing with these problems, in particular the surveys of Berrill (1952),
Abeloos (1954), Stolte (1955) and Avel (1959). Recent physiological
studies have been reviewed by Laverack (1963).
In the present article we shall limit our discussion to some of the
problems that have been studied in recent years, referring to the earher
work only in so far as it provides a fundamental basis. One of the
essential problems arising from the study of regeneration is that of the
origin of regenerative elements, and their contribution to the elaboration
of the blastema. This problem still remains a live issue, even though it
has been examined over a long period. What happens to the regeneration
bud indeed depends on the presence or absence of certain blastocytes.
155
HENRIETTE HERLANT-MEEWIS
Laboratoire de Zoologie: Histologie Comparée,
Université de Bruxelles, Belgium
I. Introduction
155
II. Blastema Formation
156
A. Regenerative Elements
156
B. Biochemical Factors
172
C. Role of the Nervous System
174
III. Differentiation of the Regeneration Bud
187
A. Caudal Regeneration
187
B. Cephalic Regeneration
189
IV. Importance of the Nervous System in Morphogenesis
194
V. Endocrine Role of the Nervous System
196
A. Experimental Facts
197
B. Histophysiological Bases
203
VI. General Conclusions
209
References
211
I. Introduction
Annelids provide excellent material for the study of regeneration.
Their relatively simple structure facilitates analysis of the regenerative
processes and, in addition, they also have a very high capacity for
regeneration.
Since the end of the last century, numerous workers have dealt with
the many aspects of these phenomena as revealed in experimental regeneration as well as in the varied modes of asexual reproduction.
There are many up-to-date and comprehensive surveys of the work
dealing with these problems, in particular the surveys of Berrill (1952),
Abeloos (1954), Stolte (1955) and Avel (1959). Recent physiological
studies have been reviewed by Laverack (1963).
In the present article we shall limit our discussion to some of the
problems that have been studied in recent years, referring to the earher
work only in so far as it provides a fundamental basis. One of the
essential problems arising from the study of regeneration is that of the
origin of regenerative elements, and their contribution to the elaboration
of the blastema. This problem still remains a live issue, even though it
has been examined over a long period. What happens to the regeneration
bud indeed depends on the presence or absence of certain blastocytes.
155