84 CALIFORNIA ACADEMY OF SCIENCES. 



Upon blocks of lava. Sticks, twigs, kelp, sea grass, and in 

 a few cases bones of defunct sea birds, were used as build- 

 ing material, and a little sea grass spread over tlie top as a 

 lining, no attempt being made to form anything more than 

 a mere platform eighteen inches or two feet in diamater, 

 and in nests of a single ^^ear's growth four or five inches in 

 depth. At this date, April 12th, most of the nests con- 

 tained young ranging from those just hatched to the full- 

 fledged birds capable of flying. 



Many nests, however, contained eggs, and by careful 

 selection about twenty sets were found that were fresh, or 

 nearly so; others taken at random proved to be all more or 

 less incubated. The usual set seems to be three; a few nests 

 contained two and were probably not complete; while but 

 one set of four was found. The fresh eggs were perfectly 

 white, but as incubation began they became stained from 

 the damp, decaying sfeaweed and kelp, which forms the 

 liniag of the nest, and by the time they had been in the 

 nest two weeks it was diflicult to tell what the original color 

 had been. An oologist (?) whom I presented with a set of 

 three stained eggs reported that he had cleaned them so 

 thoroughly that they were much finer specimens than any of 

 my fresh ones. When asked to describe the method used 

 he informed me that he simply rubbed them wdth sandpaper 

 until the shell was as thin as he considered safe. This 

 method may be of value, but will hardly come into general 

 use. A set taken at random from the collection of twenty- 

 five, and which is perhaps a fair average as to size, measures 

 in millimeters 83 x 48 ; 85 x 48 ; 72 x 50. 



The birds at this colony did not appear to be very wild, 

 only flying up Avhen we had approached to within fifty or 

 sixty yards and settling down again as soon as we had passed 

 by. Flocks of from five or six to twenty were constantly ar- 

 riving from far out at sea, flying in one long line, each fol- 

 lowing directly in the track of the one next in front, and 

 but just keeping above the water until within a few hundred 



