2.--Very often, possibly always, the appearance of In the communication of the hereditary peculiarity is syphilis to children this is limited to a definite age. unknown. 3.--Atavismus, or the overleaping of one or several Never known. generations of the heredity is very frequent. Anyone who will maintain that these two forms of conveyance are the same, and both hereditary, must evidently sacrifice facts. We hold then, that a specific disease may be conveyed to the children, but that it is never hereditary; the communication is by infection. And since we regard leprosy as a specific disease we hold that it cannot be hereditary. There remains, however, the further question whether it can be conveyed to descendants by latent germinative infection. This cannot _a priori_ be denied, although we have no right to assume it from our knowledge of the lepra bacillus and of the occurrence of the disease. We have indeed sought above to point out the possibility that the lepra bacillus is attenuated in the maculo-anæsthetic form of the disease; but we know of no phenomenon which would allow us to assume that the bacillus could occasionally become quite innocuous, and call forth _no_ symptoms of disease. All this, however, proves nothing against the hypothesis; and it is always a dangerous thing to use a simple absence of knowledge either to contradict or to found a hypothesis. But we think we can supply an almost incontrovertible proof that Baumgarten’s hypothesis is wrong. It is well known that the Belgian Father Damien became a leper in the Sandwich islands. If the Father was of pure Belgian ancestry, and his disease was caused by latent hereditary bacilli, then these bacilli must have been at least several hundred years old, unless one assumes that one of his nearer ancestors had had connection with a leper, and that in this way the Father had acquired his bacilli. Against this is the explanation that the Father who tended the lepers on Molokai, with self-sacrificing love, was, through some want of care or caution, infected as he went in and out among the lepers. The choice between the two explanations does not appear to us a difficult one.