CALIFORNIA WATER BIRDS. 5 



for several miles. It was distinctly seen that their course 

 conformed to the trend of the shore, bearing to the east 

 at Monterey Bay and to the west off Point Pinos. There 

 were no large flocks, but at intervals there was quite a 

 continuous stream of individuals and little parties. Four 

 Dark-bodied Shearwaters were noticed — single birds mi- 

 grating in company with the smaller species. 



Only the forenoon of the 12th was spent upon the water. 

 Nearly as many Black-vented Shearwaters were found 

 migrating as on the previous day, but they were not so 

 far at sea, there being a haziness of the atmosphere that 

 obscured the coast-line.* The bulk doubled Point Pinos 

 from one to two miles from the shore. The movement 

 continued the whole forenoon, but its height was at nine 

 o'clock when quite a rush occurred. A Dark-bodied 

 Shearwater was taken and four others were seen. They 

 appeared singly with individuals of the lesser species. 



The sexual organs of the eight Black-vented Shear- 

 waters that were secured on these three days were in an 

 advanced stage of erotic development. The larger testis 

 of one male measured (in inches) .32 x .47 and of an- 

 other .38 x .53. The ovaries of the females exhibited a 

 corresponding development. Not the slightest indication 

 of similar functional activity was detected in other species, 

 although hundreds of specimens of Auks, Gulls, Ful- 

 mars, etc., were examined. 



The beginning of the migration of these Shearwaters 

 was apparently witnessed Aug. 27th, the last day of ob- 

 servation in the summer expedition. In January, the mi- 

 gration was evidently drawing to a close, the breeding 



* In the preceding paper I have frequently referred to the deflection to- 

 ward the land of the path of migration in the Dark-bodied Shearwater 

 and other pelagic species when the guiding coast-line was hidden from 

 view by low-hanging fogs. The migration of a species may be almost in- 

 terpolar in extent and still be modified by local conditions. 



