The surprise and horror of it all was that no matter where we traced them, whether in the prosperous rural district, in the city slums to which some had drifted, or in the more remote mountain regions, or whether it was a question of the second or the sixth generation, an appalling amount of defectiveness was everywhere found. In the course of the work of tracing various members of the family, our field worker occasionally found herself in the midst of a good family of the same name, which apparently was in no way related to the girl whose ancestry we were investigating. In such cases, there was nothing to be done but to beat a retreat and start again in another direction. However, these cases became so frequent that there gradually grew the conviction that ours must be a degenerate offshoot from an older family of better stock. Definite work was undertaken in order to locate the point at which the separation took place. Over and over, the investigation was laid aside in sheer despair of ever being able to find absolute proofs or to establish missing links in the testimony. Then some freshly discovered facts, that came often quite unexpectedly, would throw new light on the situation, and the work would be resumed. The great-great-grandfather of Deborah was Martin Kallikak.[1] That we knew. We had also traced the good family, before alluded to, back to an ancestor belonging to an older generation than this Martin Kallikak, but bearing the same name. He was the father of a large family. His eldest son was named Frederick, but there was no son by the name of Martin. Consequently, no connection could be made. Many months later, a granddaughter of Martin revealed in a burst of confidence the situation. She told us (and this was afterwards fully verified) that Martin had a _half brother_ Frederick,--and that Martin never had an own brother “because,” as she now naïvely expressed it, “you see, his mother had him before she was married.” Deeper scrutiny into the life of Martin Kallikak Sr., which was made possible through well-preserved family records, enabled us to complete the story. [1] All names, both Christian and sur-names, are fictitious.