74 SCIENCE AND PHILOSOPHY OF THE ORGANISM 



differences with regard to germinal specific pre-formation 

 do not agree in any way with the systematic position of 

 the animals exhibiting them ; for, strange as it would be 

 if there were two utterly different kinds of morphogenesis, 

 it would be still more strange if there were differences 

 in morphogenesis which were totally unconnected with 

 systematic relationship : the ctenophores behaving differently 

 from the medusae, and Amphioxus differently from ascidians. 



SOME NEW RESULTS CONCERNING RESTITUTIONS 



We now might close this chapter, which has chiefly 

 dealt with the disproof of a certain sort of ontogenetic 

 theories, and therefore has been almost negative in its 

 character, did it not seem desirable to add at least a few 

 words about the later discoveries relating to morphogenetic 

 restorations of the adult. We have learnt that Weismann 

 created his concept of " reserve plasma ' : to account for 

 what little he knew about " restitutions " : that is, about the 

 restoration of lost parts : he only knew regeneration proper 

 in animals and the formation of adventitious buds in plants. 

 It is common to both of these phenomena that they take 

 their origin frcfm typically localised points of the body in 

 every case ; each time they occur a certain well-defined 

 part of the body is charged with the restoration of the lost 

 parts. To explain such cases Weismann's hypothesis was 

 quite adequate, at least in a logical sense. But at present, 

 as we shall discuss more fully in another chapter, we know 

 of some very widespread forms of restitution, in which 

 what is to be done for a replacement of the lost is not 

 entrusted to one typical part of the body in every case, 



