64 FEDICULARIS CANADENSIS. COMMON WOOD-BETONY. 



altered from true leaves, forming a verticil under the spike of 

 flowers. We see by tin's that the leaves had been pretty well 

 developed before the drawing' in of the spiral coil commenced, 

 and the lesson taught us by our flower is therefore this, — that 

 the matter of time in the acceleration and retardation of develop- 

 ment is the main cause of many of the varied forms found in 

 vegetation. When the accelerated motion precedes leaf devel- 

 opment, as in many plants it does, there may be but very small 

 bracts, or even no bracts at all. In most other species of Pedicu- 

 laris the development is regular, and the involucral-like circle 

 of bracteal leaves does not exist. 



A further lesson we may gather from the flowers. The 

 bracts — the small leaflets among the flowers — are changed 

 leaves, and the flowers which spring from the axils are analogous 

 to the branches which spring from the axillary bud at the base 

 of the perfect leaf. A flower is, therefore, a modified branch, as 

 the bract is a modified leaf. In many flowers we can trace the 

 relations of the floral parts to leaves and branches; but in 

 this the arrestation has been so severe that we lose all resem- 

 blances in the flower, and we cannot tell whether the corolla is 

 made up of a single leaf or several. The attention of the stu- 

 dent is directed to this point because here will ultimately be 

 found the full explanation of the reason why flowers are some- 

 times of very peculiar forms. 



Generally, we can tell what form the seed-vessel will assume 

 before the petals or the corolla fade ; but in this Pedicularis, the 

 capsule continues to grow, and ultimately assumes a sword-like 

 beak, projecting beyond the calyx. (See Fig. 2.) When mature, 

 it opens by a slit on the upper side through which the ripe 

 seeds escape. Altogether it is a very interesting plant to study, 

 as well as a pretty object to look at for those who wish to enjoy 

 only the external beauty of nature. 



EXPLANATION OF THE Plate. — 1. A single branch from a root-stock. — 2. Calyx and mature 

 seed-vessel. 



