CHAPTER III 



ANATOMY 



WHILE the morphologist deals mainly with the external 

 form of the organs of the plant's body, the anatomist 

 inquires into the internal structure of those same organs, 

 and investigates the arrangement of the tissues of which 

 they are composed. 



The plant body, like that of the animal, is built up 

 of a number of different tissues, each of which has its 

 function to perform in the economy of the whole 

 organism. In the animals there are bones, muscles, 

 nerve fibres, fat, and so on ; in plants there are wood, 

 ground tissue or parenchyma, strengthening tissue or 

 sclerenchyma, and so on. The physiological functions 

 performed by each of these sets of tissues is generally the 

 same throughout the whole animal and plant kingdom. 

 Thus the bones, for example, whatever their shape or 

 arrangement, form the support of the body, and to 

 them the muscles are attached ; the nerves, whatever 

 their plan of distribution, are the channels through 

 which stimuli and nervous messages are passed. In 

 plants, whatever its structure, the wood serves as the 

 channel for the conduction of water ; and the scleren- 

 chyma, wherever it may be placed, is there for the purpose 

 of strengthening or protecting the organ in which it 

 develops. Hence, though it is neither wise nor possible 

 to divorce entirely the study of anatomy from that of 



