90 THE NAUTILUS. 



The reviser usually has only one aim, or should have only 

 one aim in mind, and that is to achieve stability by applying 

 the rules of the international code consistently, no matter 

 how much he may dislike to so do. No nomenclatorial 

 stability can be achieved if each of us follows an independent 

 method. A catalog of the kind above referred to would make 

 a quick revision possible, the main points of which would 

 stand for a long time to come, and the minor shift could 

 easily be kept current by the small force that should pre- 

 pare the cards for the new things published year by year., 

 I wish to heartily recommend this undertaking to the National 

 Research Council. I am sure that the whole zoological frater- 

 nity, yes, not only zoological but botanical fraternity, would 

 be grateful for such a work. 



Another point that should find expression in this review 

 is the fallacy, or should I say dogma, entertained by many 

 that the soft anatomy of mollusks expresses more nearly the) 

 true phylogenetic relationship than does the shell. It has 

 come to be believed, why I do not know, that shell characters 

 are readily modified, and that the soft parts only remain con- 

 stant. The facts adduced by our breeding of Cerions do not 

 accord with this. Here, at least, we have found the shell 

 characters not affected by changed environment. By hybri- 

 dization we have produced not only changes in shell charac- 

 ters but even greater changes in the organization of the soft 

 parts. This would show that the soft parts are at least aa 

 readily changeable, if not more so, than the skeletal char- 

 acters. Furthermore, we should not lose sight of the fact 

 that the gastropod shell, in its nuclear whorls, retains a lot 

 of embryologic and subsequent metamorphic developmental 

 history which is largely, if not entirely, lost in the adult 

 anatomy of the animal. The shell therefore furnishes ever 

 so much more phylogenetic information than the adult soft 

 parts, since it records almost the complete ontogeny of the 

 species. No single set of characters tells the whole story 

 shell, cytology, embryology, anatomy, not to forget physio- 

 logy, all furnish helpful hints to a complete understanding, 

 and Professor Morse 's notes and figures will prove exceedingly 

 useful to all of us who may not have ready access to living 

 material. 



