( 125 ) 



years later (1853), simultaneously with Bernard and Brown-Sdquard, 

 he discovered the vaso-constrictor action of the cervical sympathetic. 

 Three years later, anticipating by ten years the main principle 

 established by V. Gudden, he published his discovery of the trophic 

 influence of the retina upon the optic nerve fibres. — A. D. W. 



Through the kindness of my friend A. D. Waller, M.D., F.R.S., 

 I am able to reproduce two historical figures, the one of diapedesis, 

 and the other a pencil drawing by Mrs. A. Waller showing the 

 structural changes following section of the anterior nerve root. " A, 

 posterior root fibres with ganglion globules c ; b, anterior root dis- 

 organized ; d, mixed nerve consisting of normal sensitive fibres and 

 disorganized motor fibres." 



There are many " omitted chapters." The reason is obvious. I 

 had hoped to be able to write on the relations of Comparative 

 Anatomy to Medicine, of Evolution, and of the " Origin of Species," as 

 the " turning point in the history of Biology." I was unable, for 



SIR RICHARD OWEN. 



reasons I need not mention, to obtain a portrait of Charles Darwin, 

 but, thanks to Messrs. Mayall & Co., I have obtained one of Sir 

 RICHARD OWEN, who was born at Lancaster (1804-1880). There 

 i i 



