induced to believe that there was more truthfulness in this matter than he had supposed, and to accept it as a fact redounding to the glory of the Sovereign Creator, to whom all things are possible.” [5] ‘_Rerum Muscoviticarum Commentarii_,’ 1549. See Appendix C. [6] Author of ‘_Liber de Causis, seu de Principiis et Originibus Naturæ_,’ &c. Shortly after the publication of the above narrative by Sigismund von Herberstein, and probably in allusion to it, Girolamo Cardano, of Pavia, carefully discussed the phenomenon in question in his work ‘_De Rerum Naturâ_,’[7] printed at Nürnberg in 1557. He endeavoured to expose the absurdity of the statements made concerning this “animal-plant,” and explained the physical impossibility of its existence in the manner described. He argued that if it had blood it must have a heart, and that the soil in which a plant grows is not fitted to supply a heart with movement and vital heat. He also pointed out that embryo animals, especially, require warmth for their development from the _ovum_, which they could not obtain if raised from a seed planted in the earth, demonstrating clearly enough that no warm-blooded animal could exist thus organically fastened to the earth. In reply, however, to a possible question suggested by himself, why there should be no plant-animal on land, seeing that there are zoophytes in the sea, he, with the weakness and indecision which were innate in his character, admitted that “where the atmosphere was thick and dense there might, perhaps, be a plant having sensation, and also imperfect flesh, such as that of mollusks and fishes.” [7] Lib. vi. cap. 22. This weak point in his argument laid him open to the criticism of his relentless enemy, Julius Cæsar Scaliger. Always on the watch to wound and harass Cardano with cutting satire and irritating gibes, this caustic persecutor lost no time in making his attack. In one of his “_Exercitationes_”[8] he thus personally addressed the object of his sneering disparagement:-- [8] ‘_Exotericarum Exercitationum_,’ lib. xv., “_De Subtilitate_”; _ad Hieronymum Cardanum Exercit._ 181, cap. 29. Frankfort, 1557. See Appendix D.