594 



THE FORMS OF TISSUES 



[CH. 



divided, according to the" theoretical plan, into about sixty-four 

 cells; and making due allowance for the changes which mutual 

 tensions and tractions bring about, increasing in complexity with 

 each succeeding stage, we can see, even at this advanced and 



"DC d 



Fig. 242. Theoretical arrangement of successive partitions in a discoid cell; 

 for comparison with Figs. 230 and 241. 



complicated stage, a very considerable resemblance between the 

 actual picture and the diagram which we have here constructed 

 in obedience to a few simple rules. 



Fig. 243. Theoretical division of a discoid cell into sixty-four chambers: no 

 allowance being made for the mutual tractions of the cell- walls. 



In like manner, in the annexed figures representing sections 

 through a young embryo of a moss, we have little difficulty in 

 discerning the successive stages which must have intervened between 

 the two stages shewn: so as to lead from the just divided or dividing 

 quadrants (a), to the stage (6) in which a well-marked epidermal 



