18 INTRODUCTION. 



such as Ceramhim rulirum and Laurencia jjinnatifida, lose 

 their fine colour when growing near high-tide mark, the 

 former becoming a dirty white or yellow, and the latter a 

 kind of olive-green. The same may be said of Chondrus 

 crispus, which is purj)le in deep water, and green when 

 growing in shallow pools. I have often observed the 

 iridescence of this plant. This iridescence, 1 understand, is 

 still more remarkable in Cystoseira ericoides, but it is rarely 

 found on our western shores. 



Having spoken of the laws of nature, allow me to remind 

 my young friends of the great danger of putting Nature in 

 the place of God, and of forgetting that the God of nature 

 is also the God of grace. It Would not avail us that we 

 admired liis manifold works of nature, if we were not in- 

 terested in the greatest and most wonderful of all his works 

 — the work of Redemption through his Son, Jesus Christ. 



"The Lord of all, Himself through aU diffused, 

 Sustains, and is the life of all that lives. 

 Nature is but a name for an effect, 

 Whose cause is God. He feeds the sacred fire 

 By which the mighty process is maintained, 

 Who sleeps not, — is not weary ; in whose designs 

 No flaw deforms, no difficulty thwarts, 

 And whose beneficence no change exhausts." 



