THE DEHISCENCE OF ANTHERS BY APICAL PORES. 207 



must 



quite untouched. Some of the major characteristics, how- 

 ever, seem to be significant. To these three types belong 



gen 



species 



Among 



these the conspicuous portion of the perianth, calyx or 

 corolla, is almost without exception campanulate or more 

 generally widely patent and sometimes reflexed. The 

 stamens regularly show an elongate form and are basifixed 



The pistil is usually simple 



on long or short filaments. 



with filiform style and small, punctiform stigma, but to 

 this there are rare exceptions. 



distinguished from 



miens 



The 



number of genera assigned to this type is few. In it, de- 

 hiscence by pores seems to be the least specialized of these 



three types. The anthers are for the most part elongate 

 but rare exceptions to this general rule are to be found ; 

 the pores are not infrequently continued down the sides in 



longitudinal slits. 



In the Solanum-Cassia and the Melastomataceous types 

 there is, as compared with the preceding, a reduction of 

 the number of the stamens and the pistil is always simple, 

 usually with a punctiform but sometimes slightly lobed 



stigma. 



The minor differences exhibited by the individual genera 



and species of the Solanum-Cassia type are somewhat con- 

 fusing but the conviction of the existence of an essential 

 similarity in the organization of the flowers of the forms 

 assigned to this type becomes stronger as the material is 



Here, as everywhere else, nature seems in large 



studied, 

 measure 



© 



\ 



tural agreement of many of these genera or species from 

 widely separated families and of discontinuous geographical 

 distribution — an agreement which is often so close that 

 one would almost assert that the flowers of the several un- 

 related genera indigenous in the most widely separated por- 







