2 THE HUMAN BODY. 



proportion of artificers of various kinds; so that the new 

 commonwealth had from its first separation a consider- 

 able division of employments in it, and was, on a small 

 scale, a repetition of the parent community. In the great 

 majority of animals, however, (even those which at times, 

 multiply by budding,) a different mode of reproduction 

 occurs, one more like that by which our western lands are 

 now settled and gradually built up into Territories and 

 States. The new individual in the political world begins 

 with little differentiation; it consists of units, separated from 

 older and highly organized societies, and these units at first 

 do pretty much everything, each man for himself, with more- 

 or less efficiency. As growth takes place development also- 

 occurs; persons assume different duties and perform differ- 

 ent work until, finally, a fully organized State is formed. 

 Similarly, the body_^f oneof the higher, 

 early sta^e oFjife, meirely^ collectionof undifferentiated 

 cells, each capable of multiplication by (\\ vision, and rpfann- 

 ing more or less alLits-ariginal protoplaomic--pO4)erties: 

 and with^no spfip.iflo in^iyHunil nndowmrnt nr function 

 __The mass fOhnp, TTT.) then slowly rjiffprpn+iqi-pg info fliA. 

 various tissues, each with a predominant character and 

 duty; at the same time the majority of the cells lose their 

 primitive powers of reproduction^) though exactly how com- 

 pletely is a problem not yet sufficiently studied A In adult 

 Yertebrates it seems certain that the white bloon corpuscles 

 multiply by division: and in some cases (in the newts or 

 tritons, for example,) a limb is reproduced after amputation, 

 but exactly what cells take part in such restorative pro- 

 cesses is uncertain; we do not know if the old bone corpus- 

 cles left form new bones, old muscle-fibres new muscles, 

 and so on; though it is probable that the undifferen- 

 tiated tissues (which we have compared p. 60 to youths on 

 the look-out for an opening in life) build up the new limb. 

 Tn 3Tn~nmni1n nn such restoration occurs; an amputated leg 

 may heal at the stump but does not grow again. In the 

 healing processes the connective tissues play the main part, 

 as we might expect; their cellular elements being but little 

 modified from their primitive state (p. 105) can still multi- 



