More weeks passed and still three or four of the larvæ lived, and four full months after the original exposure I saw a larva alive and wriggling while its contemporary larvæ in the other jar had long since passed away as aged moths, leaving generations of moths' eggs and larvæ to witness this miracle, for here was a larva, venerable among his kind, a patriarch _Ephestia kuehniella_, that had actually lived through _three times the span of life accorded to his fellows_, and that still showed no sign of changing into a moth. It was very much as if a young man of twenty-one should keep the appearance of twenty-one for two hundred and fifty years! Not less remarkable than these are some recent experiments made by M. Bohn at the biological laboratories of the Sorbonne, his conclusions being that radium may so far modify various lower forms of life as to actually produce "monsters," abnormal deviations from the original type of the species. Thus tadpole monsters have been formed from tadpoles exposed four days after birth to radium rays. Some of these monsters lived for twenty-three days, and would doubtless have lived longer had they been exposed to the rays for a shorter time. No changes occur in the tadpoles treated except at the transition points of growth, as on the eighth day, when the breathing tentacles are covered by gills in the normal tadpole, but are not so covered in the monsters formed after radium treatment. These monsters take on a new form, with an increasing atrophy of the tail and a curious wrinkling of the tissues at the back of the head; in fact, they may be said to develop a new breathing apparatus, quite different from that of ordinary tadpoles. M. Bohn has obtained similar results with eggs of the toad and eggs of the sea-urchin, monsters resulting in both cases and continuing to live for a number of days or weeks after exposure to the radium. Furthermore, he has been able to accomplish with radium what Professor Loeb did with saline solutions--that is, to cause the growth of unfecundated eggs of the sea-urchin, and to advance these through several stages of their development. In other words, he has used radium _to create life_ where there would have been no life but for this strange stimulation. M. Bohn assured me of his conviction that we may in the future be able to produce new species of insects, moths, butterflies, perhaps birds and fishes, by simply treating the eggs with radium rays, the result being that interesting changes will be effected in the colouring and adornment. He also believes that, with greater quantities of radium at our disposal and a fuller understanding of its properties, it may be possible to produce new species among larger creatures, mice, rabbits, guinea-pigs, etc. It is merely a question of degree, for if new types can be produced in one species why may they not be produced in another?