( «02 ) 



less than that of the bisexual ones, and then again an individual in 

 which the male flowers are more numerous than the others, and 

 between these a long series of gradual transitions and intermediate 

 forms is found. 



Not unfrequently the number of male flowers is greatly in excess 

 of the bisexuals. I met in (his country plants of HeracJeum Sphon- 

 dylium in which the inner umbellules of the umbel of the first order 

 and all other umbels of higher order were exclusively male and 

 similar plants are also found of Pastinacn sativa and Dauciis Carota. 

 They are found spread among other individuals in which the propor- 

 tion of male to bisexual flowers is more favourable to the bisexuals 

 or where the number of males is even vei-y small. 



Some Umbelliferae are only known in an almost male form. 

 Echinophora spinosa e. g. has one bisexual flower in the middle 

 of the umbel ; all other flowers are male. Also with Meum athaman- 

 ticum and 3fip'rhis odorata we ma_y observe in (he specimens cul- 

 tivated in this coun(ry in bolanical gardens, how also (here (he 

 bisexual flower is superseded, so (hat (he umbellules often do not 

 contain more (lian one such flower. 



An invcsdgation of (he andi'o-monoecious Umbelliferae shows us 

 at once that (here is a cer(ain regularity in the way in which the 

 male flowers occur. In the fii'st place, when they appear for the 

 first time in an umbel of a certain order, their number as com- 

 pared with that of (he bisexual flowers increases as we come to 

 umbels of higher order ; and secondly, if in the peripheral umbellules 

 some male flowers occur among (he bisexual ones, their part in 

 the constitution of (he umbellules becomes greater as the umbellules 

 are more distant from (he periphery. 



Of Daucus Carota, Pastiiiaca sailva and Heracleum SpliondyUum 

 whole series of specimens may be collecled in (he neighbourhood 

 of my residence, beginning wi(li such which in all the umbels con- 

 tain only bisexual flowers up to forms which are almos( or entirely 

 (H. Sphondylium) male. Among these specimens are found in which 

 the male flowers already appear in the very first umbel of the plant 

 by the side of other specimens in which the andro-monoecious cha- 

 racter only appears in the umbels of the second order or later still 

 in those of the third or fourth order. Now it is a constant rule that 

 if they appear for the first time in an umbel of a certain order they 

 will also appear in the umbels that develop later and that their 

 number in proportion to that of the bisexual flowers in the succes- 

 sive umbels goes on increasing. 



