10 ELEMENTS OF PLANT BIOLOGY 



of general significance which can be best illustrated 

 by the lower forms of plant life. The vascular plants 

 are briefly treated : an attempt is made to outline 

 the structure and life history of the seed plant, 

 but much of the morphology is left on one side as 

 of no great interest or importance to the student 

 of general biology. Secondly, after an introductory 

 lecture on the general characters and differences 

 of animals and plants, the student is at once intro- 

 duced to the most important organic substances 

 which make up the body of the organism, and then 

 to a brief consideration of some of the physical 

 characters of organic substances and of protoplasm. 

 This is followed by an account of amoeba, and of the 

 chief functions of organisms in general, and this again by 

 a general account of the cell (Chapter VI). This line of 

 approach, entered upon before the student knows 

 anything worth mentioning of the detailed structure 

 of organisms, certainly has drawbacks, but in a 

 necessarily short course it has also great advantages, 

 because it enables the structures and activities 

 described later on to be followed with some under- 

 standing of their significance in the light of the funda- 

 mental properties and functions of organic and living 

 substance. 



The Green Plant cell, as the most fundamental 

 unit in the plant world, is dealt with in Chapter VII, 

 and then the plant cell without chlorophyll, illustrated 

 (as functioning organisms) by Yeast and Bacteria. 

 The Bacteria are considered at greater length than 

 is usual in elementary books of this scope, because 

 of their enormous importance in the general economy 

 of the world, and because, as it seems to the author, 

 it is specially desirable for medical students to get 



