118 



to tlie general observer by bis being led through Kerner's 

 investigation to notice various small and apparently quite 

 unimportant details of structure, such as the presence of 





FIG. 50. 



Fig. 50. Serratuln lyenpif, Ua protected by the eummy Involucre against a beetle 

 (Uxylhyrea funesta) and ants (Formica). (After Eerner von Marilaun). 



differently directed hairs, viscid glands, etc , which prevent 

 the access of certain insects and not of others.'' 



