MR. J. H. GURNEY ON THE ECONOMY OF THE CUCKOO. 381 
membrane, with another membrane behind it, the two being united 
below, with an orifice behind the root of the tongue (‘The Field,’ 
January 12th, 18G9, and ‘Land and Water’), just distinguishable. 
The bird was examined in a birdstuffer’s shop with a knife and a 
bradawl, but in neither communication does the writer give his 
name, signing himself “Exoniensis” in ‘Land and Water,’ and 
“Qmesitor” in ‘The Field.’ If there be an apparatus, and if it really 
is deserving the name of a pouch, it would appear to be lower 
down than that (Kinahan, in ‘ Birds of Ireland,’ vol. iii. p. 42), 
namely, in the cavity formed by the “ merrythought ” bone, 
which is rather long in the Cuckoo but otherwise quite normal. 
We must remember how emphatically the Great Bustard’s sub- 
lingual pouch was disbelieved in, until competent investigation 
established its presence. It may be that the Cuckoo for a short 
period possesses something analogous, not necessarily as an egg 
receptacle, but which may be inflated during courtship, and shrivel 
again, or have to do with its vocal powers, like the tracheal 
membrane in the male Bittern. It is not always there in June, 
for a line male shot on June 2nd, and expressly examined, did not 
show a trace of it. Macgillivray gives a good plate of the tongue 
and tapering oesophagus (‘ British Birds,’ vol. iii. plate xi), and but 
little escaped his acute eye, but he found no “ pouch,” neither did 
Hcrissant or White meet with it. 
Any one who has often skinned the Common Cuckoo or the 
Greater Spotted Cuckoo must have noticed the small size of the 
sexual organs in the male in Spring, compared with other birds. 
What this may indicate is a field for speculation ; but it is 
suggestive when taken in connection with its peculiar habits, the 
abundance of males, and lack of parental affection. In the 
Greater Spotted Cuckoo there are a number of large hairs under- 
neath, and concealed by the feathers of the body, but whether 
the same are to be found in the Common Cuckoo I cannot say. 
They are not indicated in the plates in Xitzsch’s ‘ Pterylography,’ 
so perhaps they do not exist in C. canorus. 
The hairs which sometimes fill the gizzard of a Cuckoo are, 
unquestionably, caterpillars’ hairs (Tiger Moths, etc.), but they 
penetrate the coat of the stomach in such a regular way that the 
d d 2 
