Seeking a source from which these signs may have originated, I have concluded that they may arise from two circumstances. The negative sign doubtless comes from an effort to turn the head away from something which is not desired, and that with such an intent it has gradually crystallised into an instinctive expression of negation or refusal; while the nod of affirmation or approval may have grown out of the intuitive lowering of the head, as an act of submission or acquiescence, or from reaching the head forward to receive something desired, or they may have come from these two causes conjointly. [Sidenote: ALPHABET FOR SIMIAN SPEECH] This is only one of a great many points in which the speech of Simians coincides with that of man. It is true we have no letters in our alphabet with which to represent the sounds of their speech, nor have we the phonetic equivalence of their speech in our language; but it is also true that our alphabet does not fully represent or correctly express the entire phonetic range of our own speech; but the fact that our speech is not founded upon the same phonetic basis, or built up into the same phonetic structures, is no reason that their speech is not as truly speech as our own. That there are no letters in any alphabet which represent the phonetic elements of Simian speech, is doubtless due to the fact that there has never been any demand for such; but the same genius which invented an alphabet for human speech, actuated by the same motives and led by the same incentives, could as easily invent an alphabet for Simian speech. It is not only true that the phonetic elements of our language are not represented by the characters of our alphabet, but the same is true to some extent of our words, which do not quite keep pace with human thought. In the higher types of human speech there are thousands of words and ideas which cannot be translated into or expressed by any savage tongue, because no savage ever had use for them, and no savage tongue contains their equivalence. The growth of speech is always measured by the growth of mind. They are not always of the same extent, but always bear a common ratio. It is a mental product, and must be equal to the task of coining thoughts into words. It is essential to all social order, and no community could long survive as such without it. It is as much the product of mind and matter as salt is the product of chlorine and sodium. CHAPTER VIII. Meeting with Nellie--Nellie was my Guest--Her Speech and Manners--The little Blind Girl--One of Nellie's Friends--Her Sight and Hearing--Her Toys, and how she Played with them.