“The _nahual_ is generally an old Indian with red eyes, who knows how to turn himself into a dog, woolly, black and ugly. The female witch can convert herself into a ball of fire; she has the power of flight, and at night will enter the windows and suck the blood of little children. These sorcerers will make little images of rags or of clay, then stick into them the thorn of the maguey and place them in some secret place; you can be sure that the person against whom the conjuration is practiced will feel pain in the part where the thorn is inserted. There still exist among them the medicine-men, who treat the sick by means of strange contortions, call upon the spirits, pronounce magical incantations, blow upon the part where the pain is, and draw forth from the patient thorns, worms, or pieces of stone. They know how to prepare drinks which will bring on sickness, and if the patients are cured by others the convalescents are particular to throw something of their own away, as a lock of hair, or a part of their clothing. Those who possess the evil eye can, by merely looking at children, deprive them of beauty and health, and even cause their death.”[11-*] =7.= As I have said, nowhere in the records of purely Mexican, that is, Aztecan, Nagualism do we find the word _nagual_ employed in the sense given in the passage quoted from Herrera, that is as a personal guardian spirit or tutelary genius. These tribes had, indeed, a belief in some such protecting power, and held that it was connected with the day on which each person is born. They called it the _tonalli_ of a person, a word translated to mean that which is peculiar to him, which makes his individuality, his self. The radical from which it is derived is _tona_, to warm, or to be warm, from which are also derived _tonatiuh_, the sun. _Tonalli_, which in composition loses its last syllable, is likewise the word for heat, summer, soul, spirit and day, and also for the share or portion which belongs to one. Thus, _to-tonal_ is spirit or soul in general; _no-tonal_, my spirit; _no-tonal in ipan no-tlacat_, “the sign under which I was born,” _i. e._, the astrological day-sign. From this came the verb _tonalpoa_, to count or estimate the signs, that is, to cast the horoscope of a person; and _tonalpouhque_, the diviners whose business it was to practice this art.[11-†] These _tonalpouhque_ are referred to at length by Father Sahagun.[11-‡] He distinguishes them from the _naualli_, though it is clear that they corresponded in functions to the nagualistic priests of the southern tribes. From the number and name of the day of birth they forecast the destiny of the child, and stated the power or spiritual influence which should govern its career.