whteh appear to hi dioei ions 



part; in tlie male compressed, cylindrical, of tin same shade of 

 colour as the part below it. 



The male florets are more exserted beyond the scales of the 

 capitulum, and therefore longer in proportion to if than the 

 females, which frequently pro jeet \ ery little beyond the scales. 



It is not a little remarkable, that the separation of the sexes 

 should have been so long overlooked in this unl'ortunatclv most 

 abundant of weeds; the great difference in the appearance of the 

 male and female flowers has not however passed altogether un- 

 noticed, for Roth in his Flora Germanic* *, baring described 



Strratu/a (out CnicHd) arvensis. Bays, M Variat prinin calwe im- 

 nori ovato oblongo floribus duplo rnajoribus pallidioribus, stig 

 matibus subbifidis erectfa This description, I think, there can 



be no doubt refers to the male plant. 



It is I believe a common observation, that Cairns ttrvmtii 

 rarely produces seed ; and this circumstance has been attributed 



to its increasing so much by the root: the separation of the sex.4 

 however presents n much more satisfactory explanation : and I 

 have mentioned before, that the plants of each sex mow too- 

 ther in large patches without intermixture; hence the chance of 

 impregnation being effected is much diminished. 



A useful economical application may perhaps be made of this 

 fact, particularly if the observation of Villars in his Histoirc (Us 

 Plantes de Dauphint be correctt : he says, that there is a sim- 

 ple means of destroying this plant, which is by permitting it to 

 flower, after which it dies ; if, however, it be cut down before 

 flowering, it will increase in all directions. If the seeds were 

 perfect, it does not seem that much could be gained by this 

 plan : as however there is a great chance that they may not be 

 so, should it be true that the plant dies completely after fiower- 



* Tom. ii. pttra *2. p. UO-j. t Tom. iii. p. '25. 



ing, 



