The problem of the longevity of trematode eggs, particularly of those which have been kept for varying periods of time at low temperatures to retard development is, apparently, one which has not been investigated to any great extent. It is, nevertheless, admitted that literature on such a subject is difficult to find and it may be far more extensive than the following survey would indicate.
Proceedings of the Iowa Academy of Science
©1934 Iowa Academy of Science, Inc.
Krull, Wendell H.
"Notes on the Hatchability and Infectivity of Refrigerated Eggs of Fasciola hepatica Linn,"
Proceedings of the Iowa Academy of Science, 41(1), 309-311.
Available at: https://scholarworks.uni.edu/pias/vol41/iss1/110