1 84 VIGNETTES FROM NATURE. 



chevaux de frise. At any rate, the hairy 

 fringe in the throat of the calyx of the wild 

 thyme protected its seeds against some dan- 

 ger to which they would otherwise have been 

 exposed ; and only those individuals which 

 possessed it finally survived in the struggle 

 for life. 



Such special means of protection for 

 ripening fruits or seeds are common enough 

 in nature ; but it is curious how vast is the 

 variety of form or device which they assume. 

 Here, for instance, in the bit of boggy land 

 formed by the little rill on its way through 

 the rock basin, another small labiate grows in 

 profusion, the lesser skullcap. Now skull- 

 cap takes its name from a peculiarity of its 

 own, which answers in a different way just 

 the same purpose as the interlacing hairs of 

 the wild thyme. On the back of the calyx is 

 a large scale or raised spur, which looks 

 something like the shade of an old-fashioned 

 cap while the flower is in full bloom ; but as 

 soon as the corolla has withered, the upper 



