Part 3, with 365 pages and illustrations was the main work of this series. Mall began the introduction to the third part as follows:
"The present communication is the outcome of a study of 163 pathological human embryos which I have collected during the past fifteen years. The first contribution which I made to this subject included a report of 53, and the second of 20 of these embryos. These two studies are rather anatomical in nature and do not consider the causes which produce pathological embryos, nor their relation to ordinary human monsters. A more careful study of my specimens, which have more than doubled in number during the past five years, establishes beyond doubt (1) the identity of pathological embryos and small monsters, that is many of them would have developed in real monsters if they had not been aborted, and (2) that all of them are developed from normal ova due to external influences, — in man to a condition which I shall term faulty implantation."