On the Power of Habit in Vegetables. 71 



than the natives of the same species : for when they 

 have the quantity of heat to which they were accus- 

 tomed in their native soil, they bud, put forth leaves, 

 &c, always before those which are the aborigines : 

 as may be seen, every year, in the State-House-square 

 (Philadelphia), where there are English and Ameri- 

 can Elms, in rows, along-side of each other. The 

 English ones always spread their leaves some time 

 before the American ones, because these last are na- 

 tives of a warmer climate. (See Note 4.) 



Whenever I observe vegetable productions spread 

 their leaves, or ripen their fruit, very early in the sum- 

 mer, I immediately conclude, that they would endure 

 a colder climate ; and, upon inquiry, this will, in ge- 

 neral, be found to be the case. Thus Strawberries 

 and Cherries are our earliest fruits here (in Pennsyl- 

 vania), and they both grow far to the northward. 

 Barley and Rye are our earliest grains, and they 

 grow further north than any others of the same fa- 

 mily. Indian-corn (Zea Mays) requires much heat, 

 and does not produce seed to the north. (See Note 

 5.) Wheat soon ripens here, and it grows to 55° of 

 north latitude, in Britain and Ireland. 



Those trees, whose foliage is expanded early, com- 

 monly bear very cold climates, as the Laurel, Holly, 

 and Ivy ; and those trees or vegetables, which are 

 tedious or backward in spreading their leaves, or 

 latest in bearing ripe fruit, are generally the natives 

 of warmer climates. For every vegetable, as> well as 



