61 



marsh throughout the year, and properly belong to this 

 association. The Bull Frog {Rana cateshiana), of rare occur- 

 rence, is never found away from the water, nor is the more com- 

 mon Green Frog {Rana clamata). The Leopard Frog {Rana 

 pipiens) and the Pickerel Frog {Rana palustris) leave the water, 

 but are found throughout the rest of the marsh during the 

 summer. The Peeper {Hyla pickeringii) and the Tree Toad 

 {Hyla versicolor) leave the water for the bushes and trees 

 during the summer and fall. The Toad and the Wood Frog, 

 being terrestrial, likewise leave the water, and after the 

 breeding season are found only in the drier situations. Adults 

 as well as larvae furnish food for certain of the birds and 

 fishes. The Green Heron, the Night Heron, and the two 

 Bitterns derive a large portion of their sustenance therefrom. 

 The reptiles which occur in the marsh belong properly to 

 this association. There are but three: the Snapping Turtle 

 {Chelydra serpentina) , the Painted Turtle {Chrysemys mar- 

 ginata), and the Water Snake {Natrix sipedon). All come out 

 of hibernation at about the same time, between the middle 

 and the last of March. 



III. The Cat-tail Association. 

 (Plate IV, fig. 2.) 



Not only is this association larger in extent than any of the 

 others, but in it a single plant predominates to a greater degree 

 than in either of the associations thus far considered. There 

 are two species of cat-tail, Typha latifolia and Typha angusti- 

 folia, but the former is far more abundant. The two occur 

 in very distinct patches, and seldom mingle. Within the 

 association comparatively few other plants are found, but 

 about the edges there is a mingling with the other societies, 

 as would naturally be expected. In order to determine the 

 rate of growth of Typha latifolia, stations were estabHshed 

 at three points in the area surveyed where conditions seemed 

 somewhat varied. Measurements were taken about once a 

 week during most of the growing season (from April 20 to 

 June 21), and again in the fall after growth had ceased. 

 Curves of growth were drawn (Figure 1), and from them it is 

 5 



