184 CARNEGIE INSTITUTION OF WASHINGTON. 



At Ensenada, on the shore of Guanica Bay, we were most kindly 

 received and comfortably housed by the officers of the great sugar 

 estate of Guanica Gentrale. Especially is our exiiression of gratitude 

 due to Mr. F. T. Maxwell, vice-president and general manager of the 

 Guanica Centrale, who, with characteristic energy, intelhgence, and 

 interest seemed to forestall all our wants and rendered our visit a 

 pleasure which none of us can forget. The attitude of this gentleman 

 was, howevTr, but a major instance which was supplemented by the 

 reception we were accorded by His Excellenc}- the Governor, and 

 by Major Dutcher, Messrs. Sanborn, Smyth, George D. Graves, and 

 others who contributed in many ways to facilitate our work, as when 

 Mr. Alejandro Franceschi, of Yauco, generously offered to place at 

 our service, for laboratory purposes, his house at Ballena Point. 



The fact that a great future is assured to Porto Rico renders it 

 desirable that if possible an international marine laboratory, under 

 American auspices, should be established in this growing American 

 colony. It is, however, unfortunate that the limestones of Porto Rico 

 are in most places elevated above the shore-line, leaving the harbor 

 bottoms and the strand covered with rocks that break up into fine mud, 

 which, owing to the absence of strong tides, becomes charged with sul- 

 phureted hydrogen and with carbon dioxide, due to the decomposition 

 of animal and vegetable matter. Thus we met with failure in all those 

 studies wherein it was necessary that animals be maintained alive in 

 laboratory aquaria, this being true not only at Guanica but also in 

 Condado Bay, in which one finds a remarkably rich and varied fauna 

 of fishes, echini, wonns (Cerebratulus), and medusse (Cassiopea). The 

 coral reefs of the off-lying limestone islands are rich, but close along 

 the shores of Porto Rico there are relatively few corals. The dele- 

 terious influence of Guanica Harbor is well shown where the coral reef 

 to the westward of the entrance is largely killed by the water which, 

 issuing from the harbor, is drifted along the shore by the prevailing 

 wind. The Acropora are nearly all killed, while members of the genus 

 Pontes have suffered more or less, and Favia and Siderastrea have 

 survived without apparent injury. Thus the corals suffer in proportion 

 as they are unable to withstand the presence of carbon dioxide in the 

 water. 



It thus appears that Porto Rico is surpassed by Jamaica as a site for 

 an international marine laboratory. Owing to these conditions, the 

 projected studies of Conkhn, Goldfarb, and Alayer, which depended 

 for then" success upon the purity of the water, failed to a greater or less 

 degree, whereas the other members of the expedition met with a good . 

 measure of success. Thus Professor Gerould, who came to continue 

 in the tropics the notable breeding experiments with butterflies which 

 he has for years conducted upon New England forms, collected the 

 eggs of various species of the Pieridse which were abundant in Porto 



