1877.] Natural History of Fanning’s Group. 71 
(Anous stolidus) lay their eggs ; the former on the naked branches 
of the trees, which in some instances are hardly greater in diam- 
eter than the egg itself, and the latter in well constructed nests 
of twigs in the forks of the branches of the tall trees. On 
Christmas Island the larger coral blocks answer the purpose of 
the first named, and a shallow concavity scooped in the bare 
ground that of the last. 
Most birds are guided by their instinct of self-preservation in 
selecting a site for the construction of their nests; in fact, I may 
say this seems to be a law. But in this case there is nothing on 
the one island, not found on the other, which would drive them 
to adopt these widely different habits. It is evident that they 
simply conform to their surroundings. The ground and coral 
blocks are both present on Palmyra, yet they choose the trees in 
preference, being guided probably by their taste rather than by 
a desire for protection. 
The sooty terns (Sterna fuliginosa) were breeding on Palmyra. 
Their chosen locality is the extreme eastern point of the island, 
on the bare clinker beach, almost within reach of the breakers. 
They make no attempt to construct a nest; nor do they so much 
as scoop a hole in the ground to receive their eggs, which are 
dropped apparently anywhere. They live as a community by 
themselves during the breeding season, and so great are their 
numbers that they form a cloud when driven from the ground, 
and their clamor deadens the roar of the surf. 
The Sula eyanops was breeding on Christmas Island. A few 
of the same species, all in immature plumage, were nesting on 
Palmyra. The old and the young were in no instance found nest- 
ing together on the same breeding ground ; the former were con- 
fined to Christmas, and the latter to Palmyra Island. Is it pos- 
sible that the young individuals are ostracized until they robe 
themselves in the fashionable dress ? 
The only other birds found breeding on Christmas Island 
were the red-tailed tropic-bird (Phethon rubricauda), the Æ- 
trelata parvirostris, and a new species of puffin (Puffinus), 
not yet described. The bristly-thigh curlew (Numenius fem- 
oralis), the golden-back plover (Charadrius fulvus), the Tota- 
nus semipalmatus, and a species of Tringa were common to 
both islands, but were more numerous on Palmyra. The same 
statement may be applied to the lesser frigate bird ( Tachypetes 
Palmerstoni). 
These birds constitute the whole avifauna, and are almost the 
