486 



LIFE-HISTORIES 



Fig. 316. — Sea-tangles {Lnnnnan'ti ^pp.. Sca-taiin;]e Family, Laminarvxcew). 

 Various forms more or less r{'(]iicfil in size; the larger ones often having 

 the stalk o\-er 1 m. lon^ and the exiiandecl part 2 m. (Luerssen.) — 

 These brown, leatlu'ry seaweeds are familiar objeets along our coasts. 



leaf join.s tho stalk there is a cell-mass which retains this 

 power, and from time to time exhibits it in a striking way; 

 that is to say, it forms a new pseudo-leaf at the base of the 

 old one which it eventuallj' casts off, as indicated in the figure. 

 Any mass of connected cells all of which are similar in origin 

 and character is called a Hksuc. An undifferentiated tissue, 



