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style, or stigmata separate, and curve backwards, and the 

 anthers that surround them retire and shrivel up, after 

 having lost all their pollen ; but at the same time the pollen 

 which was deposited on the outside of the style, detaches 

 itself, and the hairs that covered the surface disappear. 



"This led Cassini to call these hairs deciduous, and to 

 say that they disappear at the same time with the pollen 

 which they retained. There then remains, he says, upon the 

 style, nothing more than little asperities." 



M. Alphonse DeCandolle is yet more explicit. He 

 expresses himself thus, " the arms of the style begin to di- 

 verge. At the same time the pollen disappears, the collecting 

 hairs drop off, and the style becomes altogether smooth." 



Nevertheless a microscopical examination of these hairs 

 has satisfied me that they do not fall off, but that they offer 

 a phenomenon of which I know no other example in the vege- 

 table kingdom. They are retractile like the hairs of certain 

 Annelids, or the tentacula of snails. 



If we examine a thin longitudinal slice of a young style, 

 before the emission of the pollen, it is seen that these cylin- 

 drical hairs, a little tapering to their fine extremity, are formed 

 by an external lengthening of the epidermis, and that they 

 are perfectly simple, without articulation or partitions even at 

 their base. 



Immediately below the base of each hair, there exists in 

 the subjacent cellular tissue a cavity about equal in depth to 

 half or a third the length of the hair, continuous with its 

 cavity, and apparently filled with the same fluid. This 

 cavity however does not extend beyond the most superficial 

 stratum of the style or stigma, and has no relation to the 

 tissues situated deeper, of which mention will be made pre- 

 sently. 



This arrangement is preserved up to the time of the ex- 

 pansion of the flower, the hairs being at that time covered by 

 grains of pollen, applied over their surface, and held between 

 their interstices. 



But at this period the hairs return into the cavities formed 

 at their base among the cellular tissue ; the terminal half 

 ensheathes itself in the half situated next the base, as it by 

 degrees is returned into the cavity. The point only of the 

 hair remains projecting beyond the surface of the style, and 

 causes the asperities noticed by Cassini. Sometimes the hair, 



