THE PAST HISTORY OF PLANTS. 213 



themselves every flowering plant they come across 

 in our woods and meadows. American students 

 should get in like manner Asa Gray's Manual of 

 Botany. In the course of identifying all the 

 plants you find, you will begin to understand the 

 nature of plant life and the course of plant evo- 

 lution in a way that is quite impossible through 

 any mere book-reading. Buy also a simple platy- 

 scopic lens, and a sharp penknife to assist you in 

 dissection. Armed with these simple but useful 

 tools, you will soon make rapid and solid prog- 

 ress in the knowledge of nature. 



For further and more detailed information on 

 the laws of plant life, you cannot do better than 

 consult Kerner and Oliver's Natural History of 

 Plants., which sets forth in full an immense num- 

 ber of interesting and curious facts, in language 

 comprehensible to any attentive and careful stu- 

 dent. 



