192 SAGACITY AND MORALITY OF PLANTS. 



material in their root-stocks, before flowering. Any 

 one who has witnessed the rapidity with which the 

 flowers and spike of the Aloe are developed will see 

 how necessary such a careful and patient husbandry 

 must be to a plant called upon suddenly to expend 

 so much energy upon the act of flowering. One 

 can hardly wonder at the common tradition that the 

 Aloe only "flowers once in a hundred years." 



Most species of our native Horsetails {EqiiisetacecB) 

 have adopted the habit of producing vegetative fronds 

 at .one period of the year, and reproductive fronds at 

 another. These are usually so unlike each other 

 that many a young botanist has been led to think 

 them different plants. The stem from which both 

 shoot runs underground, and in its tissues the extra 

 material gained during the vegetative stage is stored 

 until it is required by the reproductive frond. A 

 great number of Ferns have separate fronds : one 

 set purely vegetative and the other as specially 

 reproductive. Our common Hard Fern {Blechmim 

 boreale) and Parsley Fern {Alios ones crispiis) are 

 familiar examples of this principle of division of 

 labour : whilst the Royal Fern {Osmunda regalis^ 

 has proceeded half-way in the direction of complete 

 differentiation, for its spore-bearing parts occupy the 

 upper parts of fronds whose lower pinnules are true 

 leaves. 



Plant economy, however, is confined to no 

 especial set of organs. No botanist doubts that the 



