L 

 ON THE THEORY OF THE VERTEBRATE SKULL 



Being the Croonian Lechire delivered before the Royal Society, June 17, 185S 



Roy. Soc. Proc, vol. ix., 1857-59, //• 381-457/ Ann. Nat. Hist., vol. iii.y 



i859i//- 414-439 



The necessity of discussing so great a subject as the Theory of 

 the Vertebrate Skull in the small space of time allotted by custom 

 to a lecture, has its advantages as well as its drawbacks. As, on the 

 present occasion, I shall suffer greatly from the disadvantages of the 

 limitation, I will, with your permission, avail myself to' the uttermost 

 of its benefits. It will be necessary for me to assume much that 

 I would rather demonstrate, to suppose known much that I would 

 rather set forth and explain at length ; but on the other hand, I may 

 consider myself excused from entering largely either into the history 

 of the subject, or into lengthy and controversial criticisms upon the 

 views which are, or have been, held by others. 



The biological science of the last half-century is honourably 

 distinguished from that of preceding epochs, by the constantly 

 increasing prominence of the idea, that a community of plan is dis- 

 cernible amidst the manifold diversities of organic structure. That 

 there is nothing really aberrant in nature ; that the most widely 

 different organisms are connected by a hidden bond ; that an ap- 

 parently new and isolated structure will prove, when its characters 

 are thoroughly sifted, to be only a modification of something which 

 existed before, — are propositions which are gradually assuming the 

 position of articles of faith in the mind of the investigators of 

 animated nature, and are directly, or by implication, admitted among 

 the axioms of natural history. 



And this is not wonderful ; for no living being can be attentively 



