( "iHI ) 



in tlie following days until a definite maximum is reached, after 

 wiiicli it gradually decreases again until at the end of its flowering- 

 jieriod the plant again produces bisexual flowers only. 



Hence the female flower follows the law of periodicity established 

 by DE Vries for the occurrence of anomalies of various nature with 

 other plants and it may in this respect be put on a line with such 

 anomalies. It may be compared with the increased number of leaflets 

 of Trifolium pratense quinquefolinm, with the fdled flowers of 

 Ranunculus bulbosus semiplenus, with the ramified spikes of P/rt«^(7^o 

 lanceolata ramosa, etc. 



In what follows I shall give the results obtained with the andro- 

 monoecious Umbelliferae. 



The investigations of Beijerixck '), Schllz "), Kirchner '), Mac 

 Leod *), LoEW *), Warnstorf '), and others on the sexual relations 

 of the Umbelliferae have shown that by far the most species are 

 andro-monoecious and that i)esides in some of them forms occur with 

 female or with female and asexual flowers. Male flowers appeared 

 in this family to be as common as bisexual ones. Male individuals 

 are rare, however. Until now Trinia glauca was considered the 

 only Umbellifer in Europe, known in the male form. From Schulz's 

 notes it appears, however, tliaf in the environs of Halle a. S. also 

 male plants of Oennnthe fistidosd ') and Sltun latifoUam ") occur, 

 while in this country also Heraclcum SphondyHuin can occur in the 

 male form. 



Far less general are female flowers. Schilz only mentions them 

 for [Erijni/ium cauipesin')? "), Trinia <jJanca, Finipinelln magna, 



1) Beijerinck, Gynodioecic bei Daucus Carota L. Nederlandsch Kruidicundig Arcli. 

 Tweede serie 4e Deel 1885, p. 345. 



-) August Schulz, Beitriige zur Kennlniss der Bestaubungseinrichtungcn und 

 Geschleclitsvertheilung bei den Pllanzen. Bibliotheca botanica. Bd. II 1888, Heft 10 

 und Bd. Ill 1890, Heft 17. 



•') 0. Kirchner, Flora von Stuttgart und Umgebuug 1888. 



-■•) J. Mac Leod, Over de bevruchting der bloemen in het Kempiscli gedeelte van 

 Vlaanderen. Botanisch Jaarboek Dodonaea 1893 en 1894. 



5) E. LoEw, Blütenbiologische Floristik des mittleren und nordiichen Europa 

 sowie Grönlands. 1894. 



^) G. Warnstorf Blütenbiologische Beobachtuiigen aus der Ruppiner Flora im 

 Jabre 1895. Verhandlungen des botanischeu Vereins der Provinz Brandenburg 

 Bd. XXXVIII. Berlin 1896. 



") Schulz, Beitr. I p. 47. 



*) Schulz, Beitr. I p. 48. 



^) In his note concerning this plant on page 42 of his first paper, female 

 flowers are not mentioned. So this is perhaps an error in the general summary 

 at the end of the second paper. 



56* 



