and future Prospects, 5501 



swimming-bladder of fishes the doublure of the gills ; they are 

 distinct organs, which in the foetus may or may not perform a func- 

 tion. M. Fleurens connects their presence with final, that is, 

 mechanical and biological causes, and speaks of them as " con- 

 stituting the apparatus of foetal life." This we are compelled to 

 deny as a general rule. The branchiae of the foetus in mammals and 

 birds performs no such functions as he seems disposed to assign to 

 them ; nay, what is more, he must know that they do not : his theory, 

 then, of " organs of foetal life" and of adult life, has no basis in fact, 

 unless he includes, or rather rests his doctrine on, those other organs, 

 the corpora woolfiana, suprarenal capsules, &c, organs of whose true 

 character we are still profoundly ignorant. The doublure and the 

 dedoublement organique theory, then, which is here claimed* as a dis- 

 covery in 1844, has no basis, if adopted as its author views it; but, 

 separating fact from fiction, we find in it the doctrine of type, ad- 

 vocated in the presence of M. Geoffroy himself, and published in 

 1828, that is, twenty years prior to the appearance of the ' Memoires 

 d'Anatomie et de Physiologie Comparees.' It has often happened, 

 that the substitution of a happier and more expressive phrase has 

 resuscitated a theory which had been forgotten, and made that appear 

 new which, in fact, was old : in the costume we now discuss the 

 phrase proposed {dedoublement organique), it is neither correct nor 

 happy; it is incorrect, in fact, as open to equivoque; type of forma- 

 tion was the one proposed by the anatomist f who first offered the 

 theory to. the world; it has at least the merit of implying no false 

 views, being simply a generalization of a series of facts, which may be 

 verified in the embryo — in the adult anatomically and physiologically. 

 "The type or plan of formation of certain systems of organs is double ; 

 these systems are more especially the respiratory and the reproduc- 

 tive ;"* lungs and gills are present in all, whether aerial and aquatic, 

 not with reference to the foetus as an individual, but with a view to 

 the future, and to the grand scheme upon which all animals are con- 

 structed. If the future animal, when adult, is to be aquatic, the gills 

 alone are developed and the lungs disappear ; if aerial, the lungs alone 

 acquire their full growth and the gills disappear ; if amphibious (Siren, 

 Proteus, Axolotl), both remain. These were the objections made 

 to M. Geoffroy by the author J of this view, in 1821 ; they must no 

 doubt have occurred to others. To refer these structures to pure 

 foetal purposes and uses is to go backwards in philosophical Zoology ; 

 it is no business of ours to trace the causes of such a retrograde step, 

 but, were we inclined to do so, we should unhesitatingly ascribe it to 

 a misapplication of the doctrines of a Final Cause ; a misapprehen- 

 sion of the true principles of the transcendental philosophy, which, 

 not being originally a native of France, but an importation from Ger- 

 many, did not, in that country, meet with a fitting soil for its full deve- 

 lopment ; and yet that country, abounding in genius and originality, 



* Fleurens. 



f Knox, * Medical Gazette.' \ Td. 



