Crass under swans' tongues.



51



The mass we extracted weighed slightly less than half-an-ounce and

was nearly 1| inches long by 1 inch deep in each case. Mr. Seth-

Smith very kindly took the two lumps home and examined them

carefully by dissolving them ; he writes me that they consisted of a

fibrous grass or aquatic plant (the fibres being very fine indeed,

almost like fine cotton thread), matted into the two masses. He

adds that it is a wonder that they had not closed the windpipe

by pressing the tongue upwards ; anyhow it was very fortunate for

me that he was able to help me find out the cause of the “ pouch ”

in time, as otherwise I would certainly have lost both birds before

long.



These swans are of course great grazers, hut they eat grass

with all my other birds, and as I have said ; none of these were

affected, although a fourth black-necked which died recently of

another complaint also had a similar “ pouch ” developing, which

may have contributed to his death. I shall now watch my swans

most carefully and on the first appearance of a pouch ” shall clean

it out immediately. I don’t think that I can prevent its formation

as I cannot stop the birds from grazing and I don’t know where

they pick up this particularly fibrous grass.


In the accompanying' sketch the position of the “ pouch ” and

its relative size is indicated.



