34 



FIRST LESSONS WITH PLANTS 



tached to a common point, like the bones of the 

 hand to the wrist, and the petiole shows no ten- 

 dency to continue beyond the point of their at- 

 tachment) ; and the pinnate (in which the leaflets 

 are arranged on the sides of an axis like the 

 parts of a feather). The axis is prolonged in 



the pinnate leaves, 

 and the part beyond 

 the first leaflet is 

 called a rachis. 



40. If, now, the 

 leaflets in Figs. 15, 

 23, 28 were grown to- 

 gether, what would 

 be the method of 

 attachment of the 

 main veins or ribs 

 in the resulting 

 simple leaf? If the 



FIG. 28. grape leaf (Figs. 24, 



Leaf of poison ivy. 25) were to become 



compound, would it 



be palmate or pinnate? Would the oak (Fig. 21) 

 have palmate or pinnate leaves? Why would the 

 thistle leaf (Fig. 27) become pinnate rather than 

 palmate? Let the pupil examine various kinds 

 of leaves, and determine if simple leaves are 

 either palmate- veined or pinnate- veined, 



