18 SENSIBILITY. 



Fig. 9. — Head of Fedicellaria glohifera, with teeth interlocking. 



,, 10. — The same, from Echinus miliaris, with fleshy stem and 

 blades fully open. 



,, 11. — Segment of Section of Spine of Cidaris papillata. 



,, 12 to 18. — Calcareous spicules found in ambulacral tube of 

 Arhacia pustulosa, Echinometra, and Strongylocentrotus. 



By F. W. Sutcliffe, F.R.M.S. 



IT is a curious fact, that however important or interesting a 

 subject may be, it loses its piquancy when it becomes a 

 matter of common occurrence. So it is with the subject of 

 sensibility. Wrapt up and lost in the general intricacies of every- 

 day life, many persons scarcely, if ever, give it a passing thought, 

 although there is, perhaps, no subject more wonderful or instruc- 

 tive than this subject of sensation and thought. It is not our 

 intention to enter into any elaborate examination of the subject in 

 the present paper, but only to refer to one or two considerations 

 which have a direct connection with it. 



First of all, the question arises as to what branch of science 

 our subject properly belongs. On this point alone many a fierce 

 controversy has waged, some philosophers arguing that it can only 

 be studied from the psychological standpoint, whilst others state 

 that in reality it belongs to both the psychological and physiologi- 

 cal branches of science. Be that as it may, we are inclined to 

 think that the latter statement is the best and perhaps the most 

 correct. Psychology is the science of the mind ; physiology the 

 science of life and its functions ; and how^ far the two may be 

 united is not for us to determine, but remains as a tough problem 

 for philosophers. 



Suffice it to say that, if we study this subject with determina- 

 tion, we shall succeed in solving, to a great extent, some of the 

 mysteries connected with the nervous centres of life in spite of 

 their complexity. At least, we shall find that beneath this com- 

 plexity there lies a series of simple laws and common principles 

 easy of comprehension, and not more formidable than the ele- 

 mentary properties we find underlying all forms of vitality. 



