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HANDBOOK OF NATURE STUDY 



which grow flat on the ground. This heart-shaped plantlet, 

 called a prothallus, is the first state of a fern. From some 



FIG. 44. CLAYTON'S FERN. Osmunda Claytonia. 



A part of a fertile frond, much reduced ; to the right, some spore cases, 

 slightly enlarged. 



