“Whilst I knew them, for a period of two years, there was not the slightest tendency towards a difference in body or mind; external influences seemed powerless to produce any dissimilarity.”

The mother of two other twins, after describing how they were ill simultaneously up to the age of fifteen, adds, that they shed their first milk-teeth within a few hours of each other.

Trousseau has a very remarkable case (in the chapter on Asthma) in his important work Clinique M. edicale. (In the edition of 1873 it is in vol. ii. p. 473.) It was quoted at length in the original French, in Mr. Darwin’s Variation under Domestication, vol. ii. p. 252.  The following is a translation:—­

“I attended twin brothers so extraordinarily alike, that it was impossible for me to tell which was which, without seeing them side by side.  But their physical likeness extended still deeper, for they had, so to speak, a yet more remarkable pathological resemblance.  Thus, one of them, whom I saw at the Neothermes at Paris, suffering from rheumatic ophthalmia, said to me, ’At this instant my brother must be having an ophthalmia like mine;’ and, as I had exclaimed against such an assertion, he showed me a few days afterwards a letter just received by him from his brother, who was at that time at Vienna, and who expressed himself in these words—­’I have my ophthalmia; you must be having yours.’  However singular this story may appear, the fact is none the less exact; it has not been told to me by others, but I have seen it myself; and I have seen other analogous cases in my practice.  These twins were also asthmatic, and asthmatic to a frightful degree.  Though born in Marseilles, they were never able to stay in that town, where their business affairs required them to go, without having an attack.  Still more strange, it was sufficient for them to get away only as far as Toulon in order to be cured of the attack caught at Marseilles.  They travelled continually, and in all countries, on business affairs, and they remarked that certain localities were extremely hurtful to them, and that in others they were free from all asthmatic symptoms.”

I do not like to pass over here a most dramatic tale in the Psychologie Morbide of Dr. J. Moreau (de Tours), M. edecin de l’Hospice de Bicetre.  Paris, 1859, p. 172.  He speaks “of two twin brothers who had been confined, on account of monomania, at Bicetre":—­

“Physically the two young men are so nearly alike that the one is easily mistaken for the other.  Morally, their resemblance is no less complete, and is most remarkable in its details.  Thus, their dominant ideas are absolutely the same.  They both consider themselves subject to imaginary persecutions; the same enemies have sworn their destruction, and employ the same means to effect it.  Both have hallucinations of hearing.  They are both of them melancholy and morose; they never address a word to anybody, and will hardly answer the questions that