114 ORGANS AND FUNCTIONS OF PLANTS. 



other parts have received from naturalists the same 

 scientific names. 



The seed-organ l is usually of an egg-oblong form, 

 and according as it may or may not unite by adhesion 

 with the sides of the flower-cup, it is in some species 

 placed above, and in others below the other parts of 

 the flowers ; consisting, in some instances, of one cell, 

 in others of two or more cells, in which the seeds, one 

 or many in number, are contained. The modern theo- 

 retical views of this structure are given below under 

 Theory of Metamorphosis. 



Gaertner describes the seed-organs before fecun- 

 dation as composed simply of small cells, which 

 ultimately become the chambers in which the minute 

 globules originate that are to form the seeds. 



Mr. R. Brown observed in fragrant coltsfoot, and 

 other plants, two thread-like cords running from the 

 base of the seed to the base of the style, for the purpose, 

 as he conceived, of conveying nourishment ; and there 

 is a similar connection between the stem bulbs and 

 the stem in the tiger lily. 



Linnaeus describes certain seeds as naked ; but the 

 envelope 2 of the seed-organ is, with very few excep- 

 tions, such as in firs and pines, and the sago plant, never 

 wanting, though sometimes it is so thin as not to be 

 easily seen. It is always composed of an outer mem- 

 brane 3 , a middle membrane 4 , and an inner membrane 5 , 



(l) In Latin, Ovarium. 



(2) In Latin, Pericarpium. (3) In Latin, Epicurpium. 



(4) In Latin, Mesocarpium or Sarcocarpium. 



(5) In Latin, Endocarpium. 



