INTRODUCTION TO BOTANY. xlv 



twenty-five to thirty feet in circumference. See Flora, under 

 Oak. 



Duration of Trees. 



The olive may live three hundred years ; the oak nearly 

 six hundred. The cedars of Lebanon appear to be indestruc- 

 tible. The baobabs, mentioned above, are supposed to be 

 nearly six thousand years old. 



Uses of Stems 



Very various : for building, food, sugar, dying : bark of the 

 oak for tanning. Stems, woods, and barks, occupy a consi- 

 derable rank in the Materia Medica. 



1 . Buds properly so called. 



Are generally composed of scales, closely tiled, containing 

 within, the rudiments of stems, branches, leaves, and the 

 organs of fructification. They are covered externally, in trees 

 of our climate, with a viscid, resinous substance ; having 

 within a close, downy texture, destined to defend the organs, 

 contained in them, from the cold. No provision of the kind 

 is made for trees of the torrid zone, nor for those, kept in our 

 green-houses. In fruit trees, the flower bud is conical and 

 swollen; that which contains leaves only, is slender, lengthened 

 out, and pointed. 



2. Turio. 



A name given to the subterraneous buds of perennial plants. 

 Thus, the part of the asparagus, which we eat, is the turio. 



3. Bulb. 



A kind of bud belonging to certain pereimial plants, parti- 

 cularly to the monocotyledons : they arc reproduced every 

 year. 



4. Bulbils. 

 A species of small, solid, or scaly buds, which being dc- 



