THE WALXUT TRIBE. 103 



The nut of the Wahiut Tree, deprived of its outer 

 fleshy shell, is of the same nature as the stone of a 

 Peach or Plum ; that is to say, it is the innermost 

 layer of the seed-vessel, growTi very hard, and sepa- 

 rating from the outer layer. At a very early period (as 

 for instance in the state of ^^. 5.), the two layers formed 

 but one homogeneous body ; and when the inside began 

 to harden, without any corresponding change in the 

 outside, still the two held firmly together by a network 

 of veins, the impressions of which give rise to the 

 channels that divide the surface of the nut into nu- 

 merous irregular compartments. 



In one respect the nut of the Walnut differs essen- 

 tially from the stone of a Peach. In the latter it is 

 not divisible into valves ; in the former it readily 

 separates into two equal valves. These are an evi- 

 dence, although only one ovule is present, yet that 

 this fruit is in reality made up of two carpels, as 

 was indicated by its two recurved stigmas. Now ex- 

 amine the valves separately ; each is cut off from the 

 other at the base, by an imperfect partition that rises 

 up from the very bottom ; but, above the base, they 

 freely communicate with each other. Their inner 

 surface is marked by numerous elevations and hollows, 

 of a most irreo-ular arranorement, besides which a 

 small plate, originating in the partition at the base, 

 but standing at right angles to it, curves upwards, 

 and cuts each valve imperfectly into two cells ; so 

 that, what with the partition at the base, and the 

 plates at right angles with it, the interior of the 



