1 66 Boeshore — The Morphological Continuity of 



For Lathraea squamaria Kerner figures basal anther-processes 

 similar to those in the above genera. 



The stamens of two species of Orobanche, also those of Aphyl- 

 lon, Epiphegus and Conopholis are figured in Plate XV, Figs. 

 25, 26, 27, 23, 22, all of which have the downwardly-directed 

 processes. 



In Orobanche coerulea the anther lobes are round above and 

 taper gradually downward into rather short processes at their 

 lower extremities, which are slightly convergent. 



In 0. minor the shape of the anther lobes is approximately 

 rectangular, with the processes given off from the sides next to 

 the filament. 



In Aphyllon the anthers are comparatively small. The fila- 

 ment is inserted above the middle of the anther lobes, with the 

 processes at their lower extremities. 



Hairs on the stamens are a constant feature in all the above. 



The parasitic Scrophulariaceae and Orobanchaceae thus have 

 a character in common. Further, this character becomes more 

 important when the function of the processes is considered, for 

 in both groups these are contrivances designed to aid in the shed- 

 ding and dissemination of the pollen grains. With regard to 

 the genus Bartsia, Knuth (29, p. 229) says of B. apula the fol- 

 lowing: "In this Dalmatian species each anther possesses a 

 downwardly-pointing process, which is pushed to one side by 

 insects, thus opening the pollen receptacle and causing pollen 

 to be sprinkled on the head and back of the visitor." 



In connection with the description of pollination in Lathraea 

 squamaria the statement is made by Knuth that the pollen can 

 not fall out until the short, blunt point of an anther receives a 

 blow from an insect. Again, under species of Orobanche the 

 following is stated: "The four anthers are laterally united, and 

 each lobe is provided with a sharp, stiff, downwardly-directed 

 process. These processes are behind the stigma, and if any- 

 thing strikes against them the bright-yellow, powdery pollen 

 falls out of the anther-lobes, and is sprinkled on the proboscis 

 or head of the visitor." 



Histologically the structure of the awns shows a striking 

 agreement throughout the genera of Scrophulariaceae and Oro- 

 banchaceae already mentioned, in that as one passes from each 

 anther lobe toward their downwardly-directed awns the epider- 



