1885.] on tlie Forms of Leaves. 201 



form had reference to former and not to present conditions. This 

 rendered the problem all the more complex and difficult. The lecture 

 was illustrated by numerous diagrams and specimens, and Sir John 

 concluded by saying the subject presented a very wide and interesting 

 iield of study, for if he were correct in his contention every one o1 

 the almost infinite forms of leaves must have some cause and 

 explanation. 



[J. L.] 



