THE 



POPULAR SCIENCE 

 MONTHLY. 



MABCH, 1884. 



FKOM MONER TO MAN. 



Br FRANCES EMILY WHITE, M. D., 



PBOFESSOR OF PHYSIOLOGY IN THE WOSIAlf's MEDICAL COLLEGE OF PENITSYLVANIA-* 



MAN has long been regarded not only as a compendium of the 

 entire animal kingdom, but as an epitome of the universe — as 

 Nature's short-hand expression of a long-continued history begun with 

 the beginning condensation of the nebulae, and still going on to the 

 development of higher types of humanity. Nature's language is hiero- 

 glyphic, and for the correct interpretation of her occult characters a 

 key is necessary. It is one of the many triumphs of modern science 

 that she has found at least a partial key to this mysterious book, and 

 it is to the unlocking of some of its secrets that your attention is in- 

 vited on this occasion. 



My subject — the development of the human body from a micro- 

 scopic speck of living matter — is a vast one, and the attempt to con- 

 dense its consideration into the space of a single hour can result, at 

 best, in a little more than a bare outline ; but even such an exposition, 

 however imperfect, may perhaps be deemed justifiable as a means of 

 inciting to further study, and it is in this hope that the task is under- 

 taken. 



In the earliest perceptible stage of its existence, the human being 

 consists of a minute apparently homogeneous mass of living matter 

 of the kind known, since the days of Von Mohl and Remak, as pro- 

 toplasm. The word means simply the first formative material, or the 

 material in which all plants and animals have their origin. That it 

 is a fact of natural history, and not a mere figment of the scientific 

 imagination, that all plants and animals originate in a common sub- 

 stance, is no longer denied. This great principle was, indeed, rccog- 



* Address delivered at the opening of the Twentj-ninth Annual Session. 



VOL. XXIV. — 37 



