Videnskabelige meddelelser

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Videnskabelige meddelelser

24

ran millions of small red sixiegged larvæ of Hydrachnids; here

and there the walls were red with larvæ. From 10/Vlll numerous

dead gnats and enormous eggmasses were found along the shore-

line. The egglaying process itselF I did not see ; it must have

taken place at other times of the day probably in the first morn-

ing hours.

Here in the laboratory we possess numerous plancton samples

from Esrom lake ; not in a single of them we have found Diplo-

(iontns; plancton samples were also taken in those days when the

gnats were hatched but we never found Hydrachnids in them.

Undoubtedly the larvæ of Diplodontiis, when the gnats have sought

the littoral region to pair and for egglaying, have mounted them

and have been carried away with them. The mounting has taken

place in the first days of August. The parasitic stage has by no

means lasted more than I4 days and normally only some few

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