What are the uses of the reflex action of the cord? 167-170 27. What illustrations are mentioned to show such uses? 167-170 28. What is the medulla oblongata? 154, 170 29. What are the functions of the medulla oblongata? 170, 171 30. What can you state of the functions of the cranial ganglia? 171, 172 31. What are the functions of the cerebellum? 172 32. What is the function of the cerebrum? 172, 174 33. In what way does the size of the brain generally indicate the character of the man? 172, 173 34. What facts show that the gray substance of the brain is insensitive? 173 35. Upon what does the faculty of language seem to depend? 174 36. What has been observed in support of this statement? 174 37. Of what importance is the reflex action of the brain? 174, 175 38. In what ways is this importance made manifest? 174, 175 * * * * * {177} CHAPTER X. THE SPECIAL SENSES. _The Production of Sensations--Variety of Sensations--General Sensibility--Pain and its Function--Special Sensation, Touch, Taste, Smell, Sight, and Hearing--The Hand, the Organ of Touch--The Sense of Touch--Delicacy of Touch--Sensation of Temperature and Weight--The Tongue the Organ of Taste--The Nerves of Taste--The Sense of Taste and its Relations with the other Senses--The Influence of Education on the Taste--The Nasal Cavities, or the organs of Smell--The Olfactory Nerve--The Uses of the Sense of Smell--The Sense of Sight--Light--The Optic Nerve--The Eyeball and its Coverings--The Function of the Iris--The Sclerotic, Choroid, and Retina--The Tears and their Function--The Movements of the Eyeball--The Function of Accommodation--The Sense of Hearing and Sound--The Ear, or the organ of Hearing--The External, Middle, and Internal Ear._ [Sidenote: 1. True centre of sensation? Place of the mind's impressions? What is it convenient to say? What further is stated?] 1. PRODUCTION OF SENSATIONS.--We have already seen that the true centre of sensation is some organ within the skull, probably among the gray masses at the base of the brain; but the mind never perceives impressions at that point; but, on the contrary, always refers them to the external organs of sensation. Hence, it is convenient to say, that those outer parts possess the property of sensibility. For instance, we say that we hear with the ear, taste with the tongue, and feel with the fingers. That this is not the exact truth is proven by the fact, that whenever the nerve connecting one of these organs with the brain is severed, it at once loses its capacity for sensation. [Sidenote: 2. Consciousness? During sleep? In profound insensibility?]