209 



a definite form, No. 4, b, that in the next figure has 

 clearly become the promise 

 or beginning of a new ter- 

 minal joint, Fig. 71, which 

 will become free when at the 

 next .moult the old shell 

 or cuticle is cast off. The 

 minute study of this process 

 has shown that the regenera- 

 tion depends practically ex- 

 clusively upon the cells of the 

 young type, and that after 

 they have grown out and ac- 

 cumulated here in this man- 

 ner, No. 3, b, some of them 

 undergo differentiation, be- 

 coming muscle cells ; others 

 change in the manner indi- 

 cated here, No. 4, where we 

 see a commencing alteration 

 of the nuclei, which is further 

 accented in Fig. 71, and leads 



, . r , u FIG. 71. SECTION THROUGH 



to such a grouping of the Cells A REGENERATING ANTENNA OF 



that the glands, which Were Oniscus. After Ost. Advanced 



originally present there, are stage, in which the young new 



c ' L joint is already shaped within the 



also reproduced. The regen- O ld shell, a, cicatricial tissue ; b, 



erative process, then, clearly regenerated tissue ; /, new joint ; 



M1 f , ' f,cuticula(old shell). Magnified. 



illustrates to us, trom another 



point of view, the great importance of the young 



type of cells. 



\ 



