THE LIFE OF A FERN. 



17 



est amount of tissue possible, as in the Onoclea, 

 Among plants of Osrmmda cinnamomea a curious 

 form is often found, where portions of the fertile 

 frond have developed sterile leaflets {pinnce), re- 

 sembling somewhat O. Claytoniana in appearance, 

 and showing that the fertile is but a differentiated 

 sterile frond. 



