72 VEGETABLE ORGANOGRAPHY. 



The style bears, moreover, in some plants, hairs which 

 have been called Collecting Hairs (pili collectores); 

 they are found in the Compositae, and they serve to ex- 

 cite the anthers, cause their dehiscence, and attract the 

 pollen to the stigmata. The Campanulaceae also present 

 collective hairs, which in position and structure appear 

 very similar to those of the Compositae ; but it is not 

 impossible that their function is slightly different. In 

 fact, the part of the pistil of the Campanulas which we 

 call from analogy by the name of stigma, appears com- 

 pletely inaccessible to the pollen at the period of flower- 

 ing, and Cassini supposes that the hairs perform perhaps 

 the function of stigmata ; this subject deserves to be 

 studied with care. 



The carpels have a greater tendency to unite together 

 than the more external organs, which is connected, 

 doubtless, with their nearer approach to one another, 

 caused as well by their position as by the pressure of the 

 outer organs. We ought then to study carefully the 

 new appearances which result from these cohesions. 

 This union may take place by the ovaries alone ; by the 

 ovaries and styles ; by the ovaries, styles, and stigmata ; 

 by the styles and stigmata, the ovaries remaining free ; 

 and, lastly, by the stigmata alone. 



"When two or more carpels are joined together by the 

 ovaries, there results an ovary composed of several partial 

 ones, which produce as many cells as there are carpels ; 

 this union takes place generally only in verticillate car- 

 pels, and there results a general ovary with cells verti- 

 cillate around a real or imaginary axis. These cells are 

 triangular, with the inner angle acute and the external 

 face convex. We shall see, in speaking of the fruit, the 

 internal conformations which result from these unions ; 

 I shall only remark, for the present, that every ovary 

 with opposite or verticillate cells, is formed by the union 



