350 ANNUAL OF SCIENTIFIC DISCOVERY. 



to the solution of the question, I very carefully dissected and ana- 

 lyzed the contents of the digestive cavity of a specimen, immediately 

 on its being brought up ; and was most amply repaid by the detection 

 of numerous Globigerince in every stage of comminution, and with 

 the contained sarcoclic matter in greater or less quantity. Whilst, 

 therefore, the detection of these organisms in the digestive cavities 

 of the Ophiocomce afforded a most conclusive proof that the Forami- 

 nifera were living on the sea-bed at the profound depth from which 

 they were obtained, the fact of the star-fishes being captured with 

 the fresh remains of the Foraminifera in their digestive cavities 

 proves that their normal habitation is at the same great depth, inas- 

 much as it has been sufficiently established that the Globigerince are 

 present only at the bottom. I may also mention that, in examining 

 a sample of the Globigerina deposit, brought up by a previous sound- 

 ing on the same spot, I detected some Echinoderm spines, which at 

 once struck me as being identical with those on the Ophiocomce^ and 

 that, on comparison, my surmise proved to be quite correct : a further 

 and very striking proof of the vitality of the Ophiocomce at the bot- 

 tom being thus afforded. 



Professor Agassiz, at a recent meeting of the Boston Society of 

 Natural History, in commenting on the existence of marine animals 

 at the great depth of twelve hundred fathoms (seven thousand five 

 hundred and sixty feet), as demonstrated by Dr. Wallech in the pre- 

 ceding paper, remarked that, in order to withstand the pressure to 

 which these animals must be subjected, without being crushed, he 

 maintained that water must penetrate their tissues very freely. The 

 fluid penetrates in fishes through minute pores communicating with 

 the venous sinuses near the heart ; these are to be seen by the naked 

 eye on the sides of the head of the herring and shad, and enable these 

 fishes to make the change from deep water in the winter to shoal 

 water in the spring, when they approach the shore to spawn. In 

 mollusks they are limited chiefly to the foot ; in echinoderms they 

 vary in different families, being sometimes in slits, and at others ad- 

 mitting water into the aquiferous system through the madreporic 

 body. 



PHYSICAL AND PHYSIOLOGICAL PROCESSES INVOLVED IN 



SENSATION. 



The following interesting paper on the above subject was read 

 before the British Association, 1861, by Dr. J. D. Morrell: 



Every one knows that when an appropriate stimulus is applied to 

 any of the organs of sense, a feeling is produced in the mind which is 

 termed, in the language of mental science, a sensation. A pin driven 

 into any of the nerves which extend themselves immediately under 

 the surface of the skin produces pain ; a ray of light falling on the 

 retina produces vision ; a sapid substance put into the mouth pro- 

 duces taste, and so forth. Now it has always been a puzzle among 

 mental philosophers to understand how it is that we can come to a 

 consciousness of external objects at all. Theories without number 

 have been formed, from the time of Plato downwards, to bridge over 

 the gulf which lies between matter and consciousness, between objects 



