THE NIDIFICATION OF CERTAIN TERNS. 85 
STERNA ANZSTHETA. The Panayan Tern. 
The most numerous of the three species of tern which breed on 
the islets in the Inner Gulf of Siam is S. anestheta, of the eges of 
which I procured 89 single specimens and 1 pair in 1917—~several of 
the former being in an advanced state of incubation. In 1918 the 
men with me collected several scores of eggs—all of which were 
singles, with the exception, again, of 1 pair. I kept the latter, and a 
selection of 24 of the single specimens. Butler, quoted by Hume 
(op. cit., p. 800) says, with regard to one lot of eggs of this bird 
taken for him by some fishermen in the Persian Gulf, in June 1878, 
that the nests contained “from two to four eggs each.”! Later he re- 
marks, in connection with a second set of eggs obtained in the following 
month, that there was “seldom more than one egg in a nest, sometimes 
two but never more,” while in a subsequent note he observes, “ lays 
bnt one single egg.” Hume makes no comment on these contradictory 
statements, and there is nothing to show whether either of the last two 
was based on Butler’s personal observations or not. Judging from my 
own experience, it would appear that (at all events so far as Siam is 
concerned ) a single egg is the usual complement, while a pair is laid 
only very occasionally. 
As regards the ground-colour of the eggs, Hume remarks 
(p. 301), that it seems “to vary from nearly pure white to a 
rich pinky stone-colour.” A number of my eggs are of a pale bluish 
tint, and two of them are entirely unmarked with the usual specks, 
spots and blotches of reddish brown or burnt sienna brown, with 
underlying paler markings. The ground-colour of the great majority 
of the eggs in my collection varies, however, from a pale stone-colour to 
almost a café-au-lait tint. 
VOL. HI, NO. FF,-1918, 
