BIRTH: GROWTH, n 



It is, however, an indefinite term, and indicates no par- 

 ticular period of development. It is not the beginning of 

 life. To understand this we must go farther back, and see 

 what is the nature of the germ, the development of which 

 will issue in birth. We may take for this purpose, the 

 seed of a plant, or the ovum of the highest animal. Both 

 alike contain something that has the power, under par- 

 ticular circumstances, of growing up into the likeness of 

 the being from which it is derived. It would be beside 

 our purpose to consider here how this portion of organized 

 matter is separated from its parent. The process belongs 

 to the subject of generation. All we have to do with, now, 

 is the fact that it is a part of a living organism that is 

 separated, and has power to develop into the likeness of 

 that from which it is cast off. How is it thus developed? 

 Formerly it was said that the seed or egg contained a 

 store of vitality laid up in it ; and inasmuch as this might 

 not show itself actively for days, months, or years, and only 

 when placed in appropriate circumstances, of heat, mois- 

 ture, etc., the vitality was said to be dormant. Now, how- 

 ever, we explain the so-called dormant condition of an 

 undeveloping seed or ovum by the fact that as no force 

 can arise by itself, so in this instance there is need of some 

 external force to be transformed by the incipient organized 

 structure into vital power, the latter being only a con- 

 venient term of expression for that power which issues in 

 growth, development, and other actions characteristic of 

 life. The formation of vegetable matter has been just 

 referred to as an example of the employment of external 

 force, namely, the light and heat of the sun, for the pur- 

 pose of decomposing certain chemical compounds, espe- 

 cially carbonic acid and ammonia; for rending asunder, 

 that is to say, the elements of which they are composed, 

 and building up a particular structure with the material in 

 this way obtained. This transformation of heat and light 

 by leaves, into vital power of growth, so to speak, is ana- 



