DEPARTMENT OF MARINE BIOLOGY. 179 



found that the eupyrene spermatozoa are separated from the apyrene 

 and are stored in the modified portion of the wall of the uterus, which has 

 elsewhere been described by the writer as the seminal receptacle. The 

 apyrenes, on the other hand, undergo degenerative changes and, together with 

 some eupyrenes which do not reach the uterus, are inclosed in a capsule 

 secreted from the walls of the bursa seminalis. Eventually the whole 

 capsulated mass is thrown off. The presence of such a mass in the bursa 

 seminalis and of an ejaculate in the vagina was taken, in those cases in which 

 they were both observed, as an indication that copulation had taken place 

 at least twice. Oviposition had not as yet commenced. 



A start was also made upon a series of experiments to discover the physio- 

 logical reactions of the two kinds of spermatozoa. Cultures in various 

 media, sterilized sea-water, lymph, fluid from the bursa seminalis diluted 

 Mith sea-water, and fluid from the albumen gland of the male also diluted 

 ■with sea-water, were grown in live cells. Sterilized sea-water was found to 

 be the most satisfactory medium. In it cultures of both kinds of sperma- 

 tozoa could be kept alive for from 60 to 72 hours when infection did not 

 occur. When kept alone the eupyrenes lived for a shorter time — 49 hours 

 in one instance. In all cases the movements of the apyrene spermatozoa 

 were carefully studied. 



A few cultures were started, in each of which was placed a small piece of 

 decaying tissue. In these cases the reaction of the eupyrene spermatozoa 

 was slow but quite positive; they moved away from the CO2 generated by 

 the tissue. The reaction of the apyrene spermatozoa was less clear; in one 

 instance there was a distinct grouping around the tissue, in the other cul- 

 tures they remained unstimulated. In all cases those eupyrene which 

 remained in the area left clear of eupyrene spermatozoa were broken down 

 and disintegrated to a greater or less degree after 12 hours. 



Report of A. L. Treadwell. 



My work at Tortugas in 1913 has been mainly a continuation of system- 

 atic work begun in earlier years, and considerable progress has now been 

 made in the preparation of a monograph of West Indian Eunicidse. The 

 closing of the laboratory before the time of sex maturity of any of these 

 annelids prevented some proposed study of their embryology. An attempt 

 was made at producing experimentally a form of collateral budding which 

 has been described in several species of the genus Trypanosyllis, but without 

 success. The results, however, indicated a possible method of controlling 

 the sex-rhythms of this animal, and it is hoped that these experiments may 

 be continued later. 



In connection with the systematic research, I wish to record my appreci- 

 ation of the skilful work done by Mr. S. C. Ball in the preparation of water- 

 color paintings of the Eunicidse. 



A Study of the Homing Instinct in the Noddy and the Sooty Tern which Nest 

 upon Bird Key, Tortugas, by John B. Watson and K. S. Lashley. 



On May 15, 1913, 12 noddies (Anous stolidus) and 12 sooty terns (Sterna 

 fuliginosa) were captured, marked by painting their feathers, and sent to 

 Key West, where they remained until May 19, when they were placed on 

 board the steamer San Marcos and taken to Galveston, Texas, in charge of 

 Mr. Lashley. 



