DEVELOPMENT OF AGARICIA. 487 



PART I. ON THE LARVAL DEVELOPMENT. 



1. General Considerations. 

 a. Breeding Season. 



The jBrst larvae of Agaricia fragilis were obtained from a colony of 

 the coral collected in a cave on the shore of Agar's Island, Bermuda, 

 on July 8th, 1907. The colony, which was about eight or nine centi- 

 meters in diameter, was brought to the laboratory in the morning 

 and placed in fresh sea water in a battery jar. In the afternoon 

 numerous pear-shaped, light brown, larvae were seen swimming about 

 in the water. Other colonies collected from a cave on Tucker's 

 Island on July 15th when placed in fresh sea water in the laboratory 

 gave off similar larvae. In 1908 larvae were obtained from seven 

 out of eleven colonies over 5 cm. in diameter collected from Long 

 Island, Bermuda, between the 22nd and 30th of June. No larvae 

 were obtained from nine colonies under 5 cm. in diameter collected 

 on June 21st and 22nd from the same place. 



These observations show that Agaricia fragilis may be found breed- 

 ing at the Bermuda Islands during the latter part of June and the first 

 part of July. 



b. Extrusion of the Larvae. 



For the purpose of obtaining the larvae, adult colonies of Agaricia 

 fragilis were collected in caves and brought to the laboratory in 

 battery jars. During the transference to the laboratory it is probable 

 that in many cases the temperature of the water containing the coral 

 was raised above the temperature of the water in the cave. Larvae 

 were often extruded in large numbers while the corals were being trans- 

 ported to the laboratory and during the few hours immediately suc- 

 ceeding this. What the factors were which produced their extrusion 

 was not determined. Usually, however, not all of the larvae were 

 extruded at this time, a certain number being seen to remain within 

 the parent colony. 



c. Form of the Larva. 



The planula, which is light brown in color, is capable of considerable 

 change of form. It may, however, be described as piriform, the 



