9 



CHAPTER II. 



STRUCTURE AND SUBSTANCE. 



" He that enlarges his curiosity after the works of Nature, demonstrably 

 multiplies the inlets to happiness ; and, therefore, the younger part of my 

 readers, to whom I dedicate this vernal speculation, must excuse me for 

 calling upon them to make use at once of the spring of the year and the 

 spring of life, and to acquire, while their minds may be impressed with new 

 images, a love of innocent pleasures, and an ardour for useful knowledge ; 

 and to rememember, that a blighted spring makes a barren year, and that the 

 vernal flowers, however beautiful and gay, ai'e only intended by Natm^e as 

 preparatives to autumnal fruits." — Dr. Johiison. 



Alg.^ form part of that great class to which Linnaeus has 

 given the name of Cryptogamia^ because they are flower- 

 less ; but, like ferns and mosses, and other plants of the 

 same great class, they have what answers the purpose of 

 flowers. In Lindley^s valuable work 'The Yegetable 

 Kingdom/ they form a portion of his first class in his 

 natural system, which he denominates Thallogens, and 

 they constitute the first order of this class, under the name 

 of Algales, which he describes as " cellular flowerless 

 plants, nourished through their whole surface by the 

 medium in which they vegetate ; living in water, or very 



