397 



pronounce unhesitatingly against these homologies and in favour of 

 incus = quadrate, and malleus = articulare. 



However, both these authors lay most stress upon ontogenetic 

 features, and their papers have, sit venia verbo, been written to 

 order. Ever since the watchword has been given out that the an- 

 cestry of the Mammalia is no longer to be looked for in the Rep- 

 tilian stock, but, with avoidance of the latter, among the Amphibia, 

 the tendency has been shown to belittle and to make light of, Sauro- 

 Mammalian resemblances, and to exaggerate those which might be 

 pressed into the service of the Amphibian advocacy. Kingsley winds 

 up his essay with a chapter on the ancestry of the Mammalia; more- 

 over he is an enthusiastic believer in the ontogenetic method, the evidence 

 of which is, in the present case, „clearly of more importance than that 

 derived from ligamentous connections or development of processes". 

 Embryology has revealed much, and it will continue to be of the 

 greatest help to the direct comparative anatomical method, but it has 

 also taught us that its powers are Hmited. Ontogeny gives a very 

 blurred and jumbled, imperfect account of the evolution of the audi- 

 tory chain ; an account which has not cleared up even such a simple 

 matter as the homology of the stapes^). On the other hand, the per- 

 sistence of a process without a function has generally a great and 

 significant back-history. The only absolute test of the correctness of 

 any of our morphological speculations is the demonstration that a 

 given feature occurs as a functional arrangement in some animal re- 

 cent or extinct, provided always we are clear about the position and 

 affinities of that creature. 



My view of the homologies of the ossicles of the ear and neigh- 

 bouring parts is as follows : I hold that the chain of bones and carti- 

 lages between the auditory capsule and the proximal part of the man- 

 dible is homologous wherever such a chain occurs; that this chain 

 in its entirety is homologous with the whole hyo-mandibula of Elasmo- 



1) An illustration of this is the following remark by HoFi^aiANN, 

 Bronn's Tierreich, Reptilien, p. 2015 — 2016: „Auf die verschiedenen 

 Arbeiten, welche über die morphologische Bedeutung des Gehör- 

 knöchelchens handeln, werde ich hier nicht weiter eingehen, und ich 

 glaube dazu um so mehr berechtigt zu sein, als alle diese Mitteilungen 

 hauptsächlich auf vergleichend- anatomischen Gründen fußen und nicht 

 auf embryologische Untersuchungen basirt sind, und doch sind nur 

 letztere im Stande, die morphologische Bedeutung des Gehörknöchelchens 

 kennen zu lernen." And what is his result? The stapes „ist nichts 

 anderes als ein Teil des knorpeligen Labyrinthes selbst". 



