THE SUB-TROPICAL ZONE. 93 



greatly extended its boundaries within the 

 limits of history ; considerable portions of 

 Egypt, -which were once covered with a rich 

 vegetation, and studded with populous cities, 

 are now sandy wastes, and cities, temples, 

 and palaces, are buried beneath the sands 

 while it bids fair to overwhelm still more and 

 more of that ancient and fertile country. But 

 we must look a little at the vegetation of this 

 part of the world. 



The papyrus is one of the most interesting 

 plants of Egypt, having been used by the 

 ancients as a material for writing upon long 

 before the invention of paper. Our word 

 " paper" is, indeed, derived from the name and 

 use of this plant. It is one of the sedge tribe, 

 (Cyperacece) inhabiting stagnant pools and lakes, 

 though sometimes found in rapid streams. The 

 stems were the part used by the ancients, arid 

 their thin plates of cellular tissue were united 

 by moistening and pressing them together, so as 

 to form a sheet, their substance being of so 

 adhesive a nature as to require no other cement. 

 Sheets of large size were thus formed. Belzoni 

 had one twenty-three feet long by eighteen 

 inches broad. Large quantities were exported 

 to Greece and Rome, where it was the only 

 material used for writings intended to be pre- 

 served, until the invention of parchment, 

 B.C. 250. Papyrus, however, still continued to 

 be in demand till the invasion of Egypt by the 

 Saracens, in the seventh century, when parch- 

 ment >vas generally substituted for it. 



