Vertebrate Skull 65 



pecuniary reward. He acted as examiner, conducting for in- 

 stance, during the years 1856 to 1S63, and again 1865 to 1870, 

 the examinations in physiology and comparative anatomy at 

 the University of London, making even an examination paper 

 feel the influence of the new spirit in biology ; and among his 

 examinees at that time there was at least one who, knowing 

 Huxley's writings, but his writings only, looked forward to the 

 viva voce test, not as a trial but as an occasion of delight. He 

 wrote almost incessantly for all editors who were prepared to 

 give adequate pay to a pen able to deal with scientific themes 

 in a manner at once exact and popular, incisive and correct. 

 During this period he was gradually passing from his first 

 anatomical love, the structure of the Invertebrates, to Verte- 

 brate work, and although he continued to take a deep interest 

 in the course of the progress of research in that group of ani- 

 mals, the publication of his great work on oceanic hydrozoa by 

 the Ray Society was the last piece of important work he wrote 

 upon any anatomical subject apart from vertebrates. His work 

 in connection with the Geological Survey naturally attracted 

 his attention most closely to vertebrates, and, towards the close 

 of the fifties, he was led to make a special study of vertebrate 

 embryology, a subject which the investigations of Kolliker and 

 others in Germany were bringing into prominence. The first 

 result of this new direction of his enquiries was embodied in a 

 Croonian Lecture delivered in 1S58 ' On the Theory of the 

 Vertebrate Skull.' Sir Richard Owen, who was at that time 

 the leading vertebrate anatomist in England, had given his 

 support to an extremely complicated view of the skull as being 

 formed of a series of expanded vertebrse moulded together. 

 The theory was really a legacy from an old German school of 

 which the chief members were Goethe, the poet, and Oken, a 

 naturalist, who was more of a metaphysical philosopher than of 

 a morphologist. Huxley pointed out the futility of attempting 

 to regard the skull as a series of segments, and of supporting 

 this view by trusting to superficial resemblances and abstract 

 reasoning, when there was a definite method by which the 

 actual building up of the skull might be followed. Following 

 the lines laid down by Rathke, another of the great Germans 

 from whose investigations he was always so willing to find 

 corroboration and assistance in his own labours, he traced the 

 5 



