ORGANS OF REPRODUCTION. 115 



a:l intimately united. These parts are very distinct in 

 the peach, but not obviously distinct in the nut. 



The outer membrane is formed of the tube of the 

 flower-cup, when the seed-organ is below this, and 

 then the pulpy part of the flower becomes the middle 

 membrane. 



The middle membrane forms the fleshy or pulpy 

 part of peaches, apples, melons, and similar fruits, but 

 in the case of thin and dry envelopes, it may be known 

 by its always containing vessels, or traces of such as 

 have been dried up by evaporation in the process of 

 ripening. The outer coat of the stone, in stone fruit, 

 belongs to this middle membrane. 



The inner membrane is that which immediately 

 encloses the seeds, and usually contains one chamber, 

 as in the cherry and filbert ; or several, as in the apple 

 and pea : in the first case, thick, hard and stony ; in 

 the second, thin and husky. This membrane has 

 three parts which require notice, the partitions and 

 the verge with its expansion, in flowers having more 

 than one petal. 



The partitions l are usually formed by the two layers 

 of the inner membrane, and alternate with the sum- 

 mits of the pistils, or their divisions, in the form of 

 vertical plates ; but sometimes they are not formed by 

 two layers, and do not alternate, when they are ab- 

 surdly called false or spurious partitions by botanists, 

 as in the poppy and the thorn apple. 



(1) In Latin, Septa, or Dissepimenta. 



I 2 



