102 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



well as females were guarding the young. When approached 

 they usually remained quiet, only making a few passes at one 

 with their beaks. The youngsters, however, were quite noisy 

 and anxious to bite. An examination of the stomachs of sev- 

 eral young disclosed the remains of flying-fish. One adult male 

 was observed with a bright red distended pouch, which seemed 

 to be unusual at that time, as all the others had dull-colored 

 ones. This same male also uttered the chuckling call so com- 

 monly heard during the mating season. Other males gave an 

 occasional harsh scream. The air above the nesting-site was 

 constantly alive with birds flying hither and thither. 



In the middle of September, 1906, Man-o'-war Birds were 

 found nesting all along the north coast of Tower Island, and 

 as far inland as the top of the island and the rim of the crater. 

 The nests were small, built of sticks, and placed in low Bur- 

 sera trees at an average of about seven feet from the ground. 

 Young in the down in all stages were found. When ap- 

 proached, the youngsters would open their bills and squeak in 

 a threatening manner. 



On Wenman Island, on September 24, 1906, a few young 

 in down were noted on the ground and on small shrubs grow- 

 ing on the ledges of a steep hillside on the northwest side of 

 the island. On the plateau on the same side, several pairs 

 were found nesting in bushes about three feet above the 

 ground. One pair had a fresh ^gg, another a newly-hatched 

 youngster. 



On a visit to Culpepper Island on September 25, 1906, a 

 number of young in the down were seen. 



A very young bird in the down, taken on Enderby Island, 

 had china-blue feet and bill, the latter tipped with white. The 

 entire skin over the body was also china-blue. 



The colors of the naked parts of birds taken on Hood in 

 the latter part of June, when the adults were in worn plumage 

 and the organs of reproduction small, were as follows : Orbital 

 ring black in adult males, red in adult females, and pale blue 

 in immature birds. Bills were pale blue in all but adult males. 



Three birds with large sexual organs were taken at 

 Academy Bay, Indefatigable Island, on July 16. Two were 

 adult females with orbital rings dark blue, gular sacs purplish. 



