14 



MOEPHOLOGY, OE COMPAEATIVE ANATOMY. 



nates above in a little bud called the plumule ; the subsequent un- 

 folding of the plumule gives birth to the first true leaves (fig. 3). 

 Here, then, we have represented all the kinds of organs of vege- 

 tation which will form the first objects of our investigation, namely 

 the root, the stem, and the leaf, together with the buds, or com- 

 pounds of rudimentary stem and leaves, which occur at all growing- 

 points of the plants possessing these organs. 



The phenomena of germination may be conveniently observed by sow- 

 ing some Turnip-seeds and Oats in a saucer of moist sand covered by a 

 bell-glass. The structure of a dicotyledonous seed may also readily be ob- 

 served bv soaking a Pea or a Bean in water, and then peeling off the rind, 

 when the parts of the embryo, as above described, may be readily observed. 



Sect. 2. THE BOOT. 



Definition, The root may be described in general terms as the 

 descending portion of the axis, destitute of leaves, buds, flowers, 

 and green colouring-matter, but provided originally with a minute 

 " root-cap" at its extremity. Another character of general although 

 not of universal application is, that it is the part of the plant which 

 penetrates into the soil, and which serves at once as an organ of 

 attachment and of nutrition. 



Fig. 4. 



Fig. 3. 



A seedling Dicotyledonous plant, 

 with an ascending axis or tigel- 

 lum and a descending axis or 

 radicle, two cotyledons, and a 

 terminal bud or plumule. 



Lily of the Valley (Convallaria majalis), 

 with a subterraneous creeping stem 

 and adventitious roots. 



The simplest representative of the root is a mere cell or tube capable 

 ot absorbing fluids. Such organs are found in the simplest plants. The 

 definition above given applies to the more highly organized plants ; but 

 even in these the root-hairs are mere cells of the character just mentioned. 



