310 



generatory development is characterized by great condensation and direct- 

 ness of the development. There is no trace of the branchial stage, and 

 the development of the two rows of processes of the terminal cup does 

 not follow the ontogenetic order." 



His final conclusion is as follows : "The data furnished, therefore, 

 by the opercula of the serpulids" give a fairly close agreement between 

 the ontogenetic stages and the probable phylogenetic ones as determined 

 by the usual criteria. The regeneratory development, however, follows a 

 course which may be modified by the character of the operation that 

 leads to the regeneration." By the "usual criteria" he means morphology, 

 etc.. so that he cannot be accused of the circulus vitiosus. 



Those who wish to review the detailed evidence given in the above 

 papers, bearing on the theory of recapitulation, will, of course, consult 

 the original papers. My main reason for quoting them is, as stated above, 

 because of their bearing on what seem to me to be grave errors in the 

 reasoning of His. Morgan and Montgomery and others who have adopted 

 similar views. The error seems to me to be, as pointed out by Griggs, in 

 the confusion of morphology and physiology. The. adult characters that 

 are supposed to be recapitulated in the ontogeny, as well as the characters 

 in ontogeny that are supposed to represent them, are morphological 

 characters solely. It matters not what new function they may have come 

 to serve, nor by what physiologic process they have come to make their 

 appearance in the recapitulating organism. The confusion arising from 

 this source colors all the argument of Montgomery, in which he endeav- 

 ors to prove that new specific characters must have some representation 

 in the ovum — a view which we must certainly agree with — and that there- 

 fore "the whole row" of cells from the ovum to the adult must be differ- 

 ent. We grant that "The whole row" is different in some way. physiolog- 

 ically different, different in its play of energies ; but it may conceivably 

 be morphologically identical up to the very point where the new 

 character is added. It is just as easy to conceive that the energy, 

 or whatever we choose to call it, that is at a certain stage in develop- 

 ment to produce a certain rib or spine or color-band on the shell of a 

 gastropod, may be handed through the row of cells reaching up to the 

 given stage, without producing a single recognizable morphologic change 

 in the row, as compared with the individual that is not to possess the new 

 character, as it is to conceive the opposite. The argument for the one 

 view is just as certainly a priori as the argument for the other view. It 



