Regeiiernt/on m Liunhricidus C73 



to regenerate is an "adaptation of the organism to definite demands 

 made upon it by conditions of life," and that it is "not the out- 

 come of primary quahties of the hving substance," "not an inherent 

 quality of the organism," as it also contradicts the view that it is 

 due to an ^'adaptation produced by natural selection."^" 



SUMMARY 



1 Pieces of Lumbriculus contaming only a single segmentate 

 capable of regenerating both a new head and tail. 



2 Regeneration from a posterior end takes place more rapidly 

 in pieces from the anterior region of the body, and gradually 

 decreases as the pieces are taken from the more posterior region of 

 the worm. 



3 A piece of a worm, when subjected to the operation of cutting 

 a few times will produce more new tissue for the same length of 

 time than when subjected to cutting only once. 



4 No relation whatsoever between the number of old segments 

 in a piece and its rate of regeneration can be found. 



5 There is no relation between the available food and the rate 

 of posterior regeneration at different levels of the worm. 



6 In regard to its regenerative capacity each worm shows 

 variations ot its own. 



7 Regenerated tails, when detached from the old part, are 

 capable of regenerating new heads, but do not produce any new 

 posterior segments. 



8 Pieces of such regenerated tails are also capable of posterior 

 as well as anterior regeneration, from the posterior and anterior 

 cut surfaces. 



9 The pigment of the regenerated head probably does not 

 arise in connection with the old pigment, but develops anew. 



10 In the case of the anterior regeneration, where only six to 

 seven (eight) segments come back, the eighth (or ninth) to the 

 tenth (or eleventh) segments of the old worm are dropped out. 



1 1 The experimental evidence, likewise that from observations^ 



'" A. Weismann: The Germ-Plasm, 1801. 



