There are some special causes which make an enquiry of this kind a work of more than usual difficulty. There is, first, the reticence of the lower castes which must be overcome before they can be induced to yield the secrets of their tribal organisation and religious life. To the average rustic the advent of a stranger, note-book in hand, who interrogates them on such subjects, suggests a possibility that he may have some ulterior objects in connection with a coming Revenue Settlement or Income Tax assessment. It requires no ordinary amount of tact and temper to overcome this barrier; and there is besides among the lower castes an uneasy suspicion that rites and ritual, which in the eyes of the average Brâhman are boorish and a survival of a degraded savagery, are a matter to be ashamed of and concealed. Mr. Greeven’s experiences in connection with the sweepers of the Eastern Districts, whose sociology he has so carefully explored, are an ample proof of this. In connection with this there is another source of difficulty in the movement which has sprung up among many castes towards claiming a higher status than is usually accorded to them. The Shâstras and other religious literature of the Brâhmans have in recent years been ransacked by a number of castes whose so-called Aryan origin is more than doubtful to support a claim to kindred with races whose descent is universally admitted. Lastly, as the local patois varies from district to district, the manners and customs of the various castes vary from one end of the Province to the other. Hence care has been taken to guard as far as possible from general statements. A custom or a mode of worship prevailing among a caste in Sahâranpur or Ballia may or may not extend as far as Aligarh on one side or Allahâbâd on the other. The exact habitat, so to speak, of these usages or beliefs can be worked out only by the associated enquiries of a much larger number of investigators. The Subject Index which has been prepared may, it is hoped, be useful from this point of view. I have specially to acknowledge the valuable work done by Surgeon-Captain H. E. Drake-Brockman in connection with Anthropometry, the results of which are given in the Introduction, where I have endeavoured to sum up in a general way some of the more obvious facts in connection with the origin of caste and some other sociological problems.