is the opening of dense stands of large emergents (Lynch, 1948-49). 
Martin et al. (1957) list, among other species, reed (See table I 
for scientific names) and cattail as weeds of duck marshes, the 
latter particularly in the southern United States. 
The study reported herein was undertaken to ascertain the 
effects of nutria activity on marsh vegetation. It was begun dur- 
ing late summer of 1954 and continued through the summer of 1956, 
and was carried out jointly by the Fur and Refuge Division, Louisiana 
Wild Life and Fisheries Commission and the United States Fish and 
Wildlife Service under the authorization of a memorandum of agreement. 
Few studies of the food habits of nutria have been made in this 
country. Atwood (1950) listed the foods noted at feeding stations 
at Lacassine National Wildlife Refuge, Louisiana. Swank and Petri- 
des (1954) studied the effect of nutria feeding on the vegetation of 
11 ponds in eastern Texas. 
We appreciate the suggestions and help of Ted O'Neil, Louisiana 
Wild Life and Fisheries Commission; John Lynch, U.S. Fish and Wild- 
life Service; and Leslie Glasgow, Louisiana State University. Per- 
sonnel of both State and Federal refuges facilitated the studies. 
The National Audubon Society and the Louisiana Fur Corporation per- 
mitted studies on their land holdings; and I am indebted to the 
managers of the two organizations, and particularly to the latter who 
aided in the construction of the exclosures. Office facilities were 
furnished by the University of Southwestern Louisiana, Lafayette, 
Louisiana. 
