649 



While probably every raorphologist will agree with van Wijhe that 

 "eine freie Endigungsweise des Ganges zwischen Haut und Somato- 



pleura war phylogenetisch wohl unverständlich", many, 



among whom I include myself, will decline to view the origin 

 and meaning of the duct in the light of its absence in Amphi- 

 oxus. Like van Wijhe, I once thought it possible that something 

 morpholgically important might come out of Bahinoglossus , morpho- 

 logically important as bearing on the ancestry of Vertebrates. But 

 since the publication of Bateson's later papers, which contain, among 

 other things, the ingenious arguments by which he attempts to show 

 the worthlessness of segmentation as a factor in phylogenetic specu- 

 lation, I have washed my hands of that animal, and place it with 

 Amphioxus and the Tunicates anywhere but in the direct line of 

 the Vertebrates. Every one knows the tale of the m'an who in buy- 

 ing an old castle bought the ancestors along with the rest of the 

 property; by which process they became his ancestors. Amphioxus, 

 the Tunicates, and indirectly Balanoglossus, were ancestral items which 

 Vertebrate zoology took over with Haeckel's Chateau en Espagne, 



To apply an apt expression of Kleinenberg's, Amphioxus and 

 Balanoglossus are simple beings, it is true, but they are too simple 

 to be the ancestors of existing Vertebrates. And, as Prof. Wieders- 

 HEiM remarks, all comparisons ofj Amphioxus with the Vertebrg,tes 

 mainly consist in negations. 



VAN Wljhe is evidently not a great believer in degeneration, 

 and he will not admit that Amphioxus shows in its ontogeny any 

 traces of such processes. The disguised argument that organs, if they 

 once existed in an animal or its ancestors, must appear somewhere or 

 other in the life history of the individual is a very dangerous one, 

 and, though possibly convenient as applied to Amphioxus, its appli- 

 cation in other cases would lead to some very startling conclusions. 



It is quite unnecessary that one should enter into a long dis- 

 cussion of rudimentary organs, but surely most of us are agreed that 

 degeneration may go so far, that organs, and whole systems of organs, 

 may disappear entirely, even from the ontogeny of the organism. 



If VAN Wijhe is so convinced of the primitive nature of Amphi- 

 oxus, it would surely be an easy task to him to show us how such 

 systems of organs as cranial nerves, sense organs, limbs, urogenital 

 system, etc. could be evolved from that simple animal. To take one 

 example. It is utterly impossible, by any twisting of the cranial 

 nervous system of higher Vertebrates, to obtain any valid comparison 

 to the supposed corresponding parts in Amphioxus, and when Ran- 



