Bur and Catkin 
It always seems matter for surprise that the round burs 
of the chestnut should grow in catkins that seemed destined to 
produce fruit-clusters of a quite different type. Here is a picture that 
emphasizes the contrast, as it shows a well developed bur in 
connection with the remains of the catkin. As the stam- 
inate and pistillate flowers of the chestnut are 
borne in different clusters, cross polleniza- 
tion is very readily effected. 
