/. D. Hague on the Guano Islands of the Pacific Ocean. 229 



features of the island resemble those of Baker's. Its surface, at 

 least on the western side, is somewhat depressed and much of it 

 is covered by a growth of purslane, grass and other vegetation 

 hke that on Baker's Island, but considerably more abundant. 

 Near the centre of the island there are one or two thickets of leaf- 

 less trees or brushwood, standing eight or ten feet high and oc- 

 cupying an area of several acres. The tops of these trees, in 

 which the birds roost, are apparently quite dead but the lower 

 parts near the roots, show signs of life after every rain. The 

 windward side of the island is formed by a succession of ridges 

 composed of coral debris with some sand and shells, running 

 parallel to the eastern beach, each one of which may, at earlier 

 stages of the island's growth, have successively formed the weath- 

 er shore. Occasionally among these ridges a sandy bed is met 

 with in which some little guano is mixed. On the lee side there 

 IS also a sandy margin of considerable width. Bits of pumice 

 and pieces ofdriftwood are scattered all over the island's surface. 

 The main deposit of guano occupies the middle part of the isl- 

 and and stretches, with some interruptions of intervening sand, 

 pearly from the north to the south end. Its surface is even and 

 in many places covered by a thick growth of purslane whose 

 tnread-like roots abound in the guano where it grows. The de- 

 posit rests on a hard coral bottom and varies in depth from six 

 inches to four feet. The fact, already observed at Baker's, that 

 "vegetation flourishes most where the guano is shallow is also 

 quite apparent here and the consequent characteristic difference 

 between the guano of the deep and shallow parts is distinctly 

 marked. The first variety, from the deeper part, is a fine pul- 

 verulent substance of reddish brown color, usually a little damp 

 in its native bed and almost quite free from roots or fibers. The 

 latter is of rather coarser texture, quite black and containing 

 Jiany delicate roots and fibers and much vegetable matter. The 

 following analvses exhibit their comparative quality. No. 1 is 

 of the deep part. No. 2 of the shallow part of the deposit. 



^isture at 21 2° Fahr 183 ^4'1 2 



Insol. in Hcriu" consumed organic) matter* 1 "95 J-OO 



Sulphuric acid IS^ 



Phosphoric acid 39-65 



Carb. acid, chlorine and aUtalies undeterm'd , 19^ 



It Will be seen that the main difference in these samples is m 

 tne volatile matters present. Discarding the water and the or- 

 ganic matter, comparative analyses of the ash would vary but little 



Some interesting pseudomorphs occur buried m the guano of 

 this island. Coral fragments of various species were found that 



