362 



SCIENCE. 



[N. S. Vol. XVIII. No. 455. 



niicroplankton from different depths piimp- 

 ing was resorted to. For this a semi- 

 rotary 'clock' force pump of one half inch 

 intake and one half inch garden hose were 

 used. This collecting was not extended 

 below a little less than 100 fathoms. The 

 volume of water that could be obtained by 

 so small a pvmap and hose was too small 

 to make the results wholly satisfactory. 

 The trial convinced us, however, that the 

 method is sound even for considerably 

 greater depths than we were prepared to 

 go, and that with a larger power pump and 

 the right sort of a filter it would be of 

 much importance. The most serious diffi- 

 culty encountered during the summer was 

 the lack of wind for propelling the 

 schooner. Night collecting proved to be 

 practically impossible most of the time on 

 this account, and much of the time during 

 the day the more sensitive organisms like 

 some radiolarians, some medusae, appen- 

 dicularia, etc., were usually dead on reach- 

 ing the laboratory when they were brought 

 from a distance of six or eight miles. 



The regular staff of the laboratory, i. e., 

 those engaged upon the survey work 

 proper, with their tasks, were as follows: 

 Wm. E. Ritter, Ph.D., professor of zoology, 

 in charge, protoehordata ; C. A. Kofoid, 

 Ph.D., assistant professor histology and 

 embryology, protozoa; H. B. Torrey, Ph.D., 

 instructor in zoology, coelenterata ; C. 0. 

 Esterly, A.B., assistant in zoology, cppe- 

 poda; J. F. Bovard, B.;S., assistant in 

 zoology, protozoa, with Professor Kofoid; 

 H. M. Evans, senior student in the univer- 

 sity, hydrography and preparateur in 

 zoology. 



In addition the following persons used 

 the laboratory for prosecuting their own 

 special studies : Dr. A. Carlson, of the Le- 

 land Stanford Jr. University, investiga- 

 tions on the comparative physiology of the 

 invertebrate heart; Mr. B. M. Davis, Los 



Angeles Normal School, investigations on 

 the notation of pelagic animals; Miss 

 Mariou Hubbard, of Wellesley College and 

 the University of California, general studies 

 on tunicata and mollusca; and Miss Mar- 

 garet Plenderson, a student of the Univer- 

 sity of California, special stiidies on the 

 coelenterates with Dr. Torrey. 



SOME RESULTS. 



No part of the summer's worJi was done 

 with greater regularity and interest than 

 the hydrographic, though only the tempera- 

 ture and the specific gravity of the water 

 were attempted. About 150 determinations 

 of each of these were recorded. This num- 

 ber is, of course, too small, particularly 

 when confined to so limited an area and 

 so brief a time, to have more than local 

 significance. Even so, however, a few facts 

 worthy of noting were brought out. It was 

 found that the specific gravity of San 

 Diego bay water was distinctly higher 

 during the period of observation than that 

 of ocean water, and that near the head of 

 the bay it was higher than in the middle 

 portion. The averages are : Ocean water, 

 1.02455+ ; bay water, middle portion (at 

 Coronado), 1.02546+ ; upper portion (off 

 National City), 1.02626+. 



Although these results are what would 

 be expected in view of the fact that San 

 Diego Bay is a land-locked, comparatively 

 shallow body of water, they are still of 

 interest particularly because it has been 

 surmised that a large subterranean inflow 

 of fresh water from the San Diego River 

 enters the bay at its upper end. While 

 these observations do not disprove the con- 

 jecture, they obviously do not support it. 

 Furthermore, the difference between ocean 

 water and bay water was somewhat greater, 

 on the average, at low tide than at high, 

 the average differences being for low water, 

 .001003+, and for high, .00087. 



Another interesting but puzzling fact was 



