2l6 



7 HE BEGINNINGS OF LIFE. 



differed very much in shape and size— some were not 

 more than xo^oo-", whilst others were as much as -i 



1 5 ( 



C0^^"=o 



^^^S^¥.i\iSii^. 





o'-o 



ooX^^oOOo'^.'^.S^no 



o ^_ o^. 







'5«p> 



.o.??,.^oo' 







o^« 



??^b;^.:^i<^?^°^o 



oo 





^Sq^ o- o 



oO^^rS-.'^c. 









O 0°' 

 CO OchO 



coo o 









"•°-°o°.S; 



o 



,0^0 O-'o 



On oO?0 



'f*o O 



o? 



^ 



^«pj( 





itYo-VoS^o^oOXoa^o^,'^. 





OO, 



O <1. 



-o 



IliJ 



oo 



od 



t ^ 



I? OOD 



c,^ o o 



or ' °'^- ' 





B 



o^So^.-ro 



i*.u o\^_nO'^c"<>'''^-° 



o ^^';CS>^ 





a. 



->o*o« 



OS 



.ooVo<>'^^ 



OO O 



^'. 



''Z 



>/^'( 



'fj 





I'll 



° o 



4 



^Vffl 



%l'- 



'3; 



'-■J -J 



ill- 



m 



fi: . ^ 



V, 



Vto^ti, 



'ir. 



lO o f> o o _ 



'oo. 



.COC 

 ^ _0 





■;t,. 





& 



"(JO o -^ 



- o 



O 





^<i 





^QoC^^.-'l^tf'^^ 



o 



n 



f^ 



'■'/^*^' 



% 



o'^Q OC o 



//; 



■:'' 





c^^^ojS^o'i'b--? 





I 





. '-.r.j = 



^'i 



i 



^y. 



'IS 



M 



Vi: 





"?^ 



I fd. 



CJ^^i^'fl 





oOo 



U 



,:\. 



& 



N 



■1 





■ 



U: 



Oat* 



00' 



.00 



o 



%o"o<>^o. 



"00 



,0 n o ' 



^0-.^S!o 



^"O-^t, 





.^? 



'<';i-!'' 



% 



M 



o tt^ 



V 



Ijll 



.'■'.j'ifi/'"l.i'':i';' !, 



o^o:<i 



O ft f* 





o^^ 





' ^ 



a 



^ 4 



t-o-O" 



V. 



■'■'Mm 



V 





V 



s 





4 



-V=/otJVM™ 



e o 



o ^yCof^Q^o 





^O 



^Joc"^ 



o 00 



J- 



(9 





/f " 





o. 







t • 



a 



Do 



J?0 



000 



— / ' 







O^^Oo 



oo 



■oG 



oo 



00 



/ 



P^o..^ 



o rj c O o Q 



/py o '^ o o^o 



0<J o t> O 



* \ 



" .3 



OqO, 



A 



O fi Q 







^ 4 



'^1 '■ 



w % 



T ^ 



^ X 



^ I 



fc- / t 



.- ^^^ 



A O t> O, 



o 



Oo 



O 



Q. 



O *J. 



'O 



poo 



^.' SS.??^i 



of*o 



.0"0^o 





.5 



'qOC 



• o 



o a 



.0 c> 











W^o o 



fl oO 







k. 



00 



eg 



o-o 





00. 



00 



O, 



o 





O O O "L 



^^o 



^ 







0^0^ 



o o 





Do ^O * 0« 







o 



Fig. 57. 



Segmentation of Embryonal Areas into Monads. ( x 1670.) 



o. First stage of differentiation. 



h. Second stage — area almost homogeneous and refractive. 



c. First traces of segmentation. 



d. Segmentation more complete — units highly refractive, 



e. Units less refractive — forming tailless corpuscles. 



/. Fully-developed Monads derived from such corpuscles. 



in diameter. Their shape was wholly irregular. Care- 

 ful examination with a jV and a 



1 '^ 



^2 



immersion ob- 



^i.*'** 



. !k Dii(fet of a 



,J 



(ran to Cj 



=;es of tbs 



J by such a I 



■ifkrical corpu 

 T: at fot hio 





rather Ic 



"■ 3r three 



ini 



( 



-if 



■ » 



^r 



"^^ 



■'^t, md slight 

 -!»§ against 



1 rapi(i' 

 nuitiber 



ii 



''I 



■;i le 



>.'ii 



u 



liad 

 in 



Hi 



inc 



IHv* 



^the 



