LESSON XXX 1 



THE GENERAL CHARACTERS OF THE HIGHER PLANTS 



IN the 27th Lesson (p. 307) it was pointed out that a 

 thorough comprehension of the structure and development 

 of Polygordius would enable the student to understand the 

 main features of the organization of all the higher animals. 



In the same way the study of the fern paves the way to 

 that of the higher groups of plants, all of which indeed, differ 

 far less from the fern than do the various animal types con- 

 sidered in Lesson XXVII from Polygordius. We saw that 

 the differences between these included matters of such im- 

 portance as the presence or absence of segmentation and of 

 lateral appendages, the characters of the skeleton, and the ' 

 structure and position of the nervous system. In the higher 

 plants, on the other hand, the essential organs root, stem, 

 and leaves are, save in details of form, size, &c., practically 

 the same in all : the tissues always consist of epidermis, 

 ground-parenchyma, and vascular bundles, the latter being 

 divisible into phloem and xylem : the growing point both of 

 stem and of root is formed of meristem, from which the per- 

 manent tissues arise ; and the growing point of the root is 



1 Readers who have not studied botany, or at least examined types 

 of the chief groups of plants, will derive little benefit from this lesson. 



