51f) ON THg ORCiAKS AND MODE OF FKCUNDATION 



ASCLEPIADEiE. 



The various statements and conjectures on the structure 

 and functions of the sexual organs in this family were 

 collected, and published in 1811, by the late Baron Jacquin, 

 in a separate volume, entitled, ' Genitalia Asclepiadearura 

 Controversa.' 



To this work, up to the period when it appeared, I may 

 refer for a complete history, and to the tenth volume of the 

 Linnean Society's Transactions, along with tli§ first of the 

 Wernerian Natiu'al History Society's Memoirs, published 

 somewhat earlier, for a slight sketch, of the subject. 



I shall here therefore only notice such statements as 

 Jacquin has either omitted or imperfectly given, and 

 continue the history to the present time. 



In 1763, Adanson correctly describes the stamina in 

 Asclepias as having their filaments united into a tube 

 surrounding the ovaria, their antherte bilocularand cohering 

 with the base of the stigma, and the pollen of each cell 

 forming a mass composed of confluent grains as in Orchi- 

 dese. He is also correct in considering the pentagonal 

 body as the stigma ; but he has entirely overlooked its 

 glands and processes, nor does he say anything respecting 

 the manner in which the pollen masses act upon or com- 

 municate their fecundating matter to it. 



In 1779, Gleichen,^ although he expressly says that in 

 young flower-buds the pollen masses are distinct from 

 those glands of the pentagonal central body to which thay 

 T16] afterwards are attached^, yet considers both masses and 

 glands as equally belonging to the anthera, the mass 

 being the receptacle of the pollen. He further states that 

 before the masses unite with the glands they are removed 

 from the cells in which they were lodged, and are found 

 firmly implanted by their sharp edge into the wall of the 

 tube which surrounds the ovaria ; that in this state a white 



jUicivscop. E'.id. p. 73, et scq. 



