170 LIFE OF BENJAMIN SILLIMAN. 



namely, a single bone or articular facet of a bone on 

 which Cuvier deemed it possible to reconstruct the entire 

 animal, is inadequate to that end. In this opinion I do not 

 coincide. I have had too frequent evidence of the potency 

 of the law of correlation of structures in an animal organ 

 ism to doubt the strength of Cuvier's proposition. But if 

 a single bone has been deemed insufficient to give the en 

 tire animal, with more reason may we doubt the efficacy of 

 a footprint. We must bear in mind the conflicting opinions 

 to which the Chirotherian impressions have given rise ; next, 

 in regard to the Ornithicnites, it is important to remember 

 that there were reptiles at the age of the New Red Sand 

 stone, the Rhynchosaurus, e. g., (see " Transactions of the 

 Cambridge Philosophical Society," Vol. VIL, Part in., p. 

 355,) which presented a singularly close approximation to 

 birds in the form and structure of their edentulous skull ; 

 and might not a corresponding modification of the feet 

 complete the resemblance of these ancient reptiles to the 

 fabled cockatrice ? A biped reptile would not be more 

 anomalous than a jerboa or kangaroo. In the foregoing 

 remarks I wish to be understood as merely indicating the 

 grounds which justify caution in assuming the existence of 

 a highly organized, warm-blooded, quick-breathing, perhaps 

 volant, feathered biped, from footprints merely. I have, 

 however, recently acquired very important additional evi 

 dence of the former existence, in the Island of New Zea 

 land, of a gigantic bird, having the same low grade of 

 organization as regards the respiratory system which I have 

 demonstrated in the Apteryx of the same island (" Zoologi 

 cal Translations," Vol. L). It is to this circumstance, per 

 haps, that Dr. Daubeny alludes in his letter to you. 'My 

 evidence is not, however, footprints, but the bones them 

 selves. If you will refer to the " Transactions of the Zo 

 ological Society," Vol. III. Part i. p. 29, you will see the first 

 indication of the gigantic struthious bird of New Zealand, 

 which vindicates Cuvier's principle, as showing what may 



