46 Travsadions of the 



Yon will, I am sure, at once see how this principle — supposing it to 

 be true — simplifies all our confusions and difficulties. We see that in 

 some plants the cohesion of leaves, normally separate, gives us the 

 bell of the campanula, or the winged flower of the pea ; that, in other 

 plants, the thickening of a leaf gives us the fleshy fruit of the apple 

 or pear ; while in others, again, cultivation changes the thin 

 fllaraents of the anther into the more leaf-like petals oi" the double 

 rose. Thus all the various points of a plant are but developments of 

 such an ideal monster as you see before you. 



But is the principle true ? Is it a fact that leaves do change after 

 this fashion, or is the whole idea but a poetical dream ? I answer — 

 it is not a dream. It is one of the most certain and well-attested /ac/s. 

 That leaves are changed or metamorphosed to serve certain ends, 

 there is not the least doubt. If you examine the leaf of the common 

 garden pea, you will find that the terminal pinna has not any lamina, 

 or blade, but consist simply of a midrib occasionally branching out 

 and forming what is called a tendril. Thus, by means of an altered 

 leaf, the plant is able to support itself. 



You are, many of you, acquainted with the curious pitchers of the 

 pitcher plant. These pitchers are leaves, the covering of the pitcher 

 is the blade, the pitcher itself is a hollow stem. Other plants 

 occasionally produce leaves, the edges of which cohere together and 

 form pitchers, or funnels. They have been observed in the pelar- 

 gonium, the tropoeolum, and the garden pea. 



There are two kinds of columbine commonly cultivaied in our 

 gardens. One kind has the flower divided into five parts, each of 

 which has a curiously recurved spur, somewhat hke a bii'd's head, 

 whence the name of the plant columbine, or aquilegia. The other 

 kind has not spurn, but is a much more open kind of flower, with 

 flatter petals These two kinds, seemingly so distinct, are not 

 separable— the one passes into the other. 



Now, not only do we find petals changing their shape, as in the 

 columbine,' but we not unfrequently find sepals and petals also 

 becoming truly leaf-like. In roses the sepals have been seen to take 

 a regular pinnate form, exactly similar to that of the normal leaves of 

 the plant, and the same change occurs occasionally in the calyx of the 

 peach, the fuchsia, the primrose, and the melon. Leafy corollas have 

 been found in roses, cabbages, wall-flowers, mallows, cherry-blossoms, 

 scabious, campanula, and a host of other plants. 



The form of the calyx and corolla is not so unlike that of a leaf as 

 is a stamen, or one of the carpels, but even these parts are sometimes 

 found assuming a regular leaf-shape. The anthers of petunias are 

 occasionally found turned into leaves, while the fllament retains its 

 nor.nal condition; and a flower of euphorbia was observed by Dr. 

 Master. , of which one-half of the anther was frondescent while the 

 other was perfect. We all know the double-rose, in which the 

 staiTiens are changed into jjctals ; and how often have we been disap- 

 pointed in finding that our rose had a green heart. This heart is 

 nothing but a leafy form taken by the carpels, and occasionally a 



