September 20, 1907] 



SCIENCE 



377 



Before criticizing the preceding quotation, 

 it is desired to call attention to Bernard's 

 geographic subdivision of the Porites of the 

 western Atlantic, the Gulf of Mexico and the 

 Caribbean Sea. They are Brazil, Curagao, 

 Trinidad, Barbados, Guadalupe, Antigua, Bar- 

 buda, Nevis Island, St. Christopher, St. 

 Bartholomew, Anguilla, Santa Cruz, St. 

 Thomas, Porto Rico, Santo Domingo, Ja- 

 maica, Belize, Vera Cruz, Florida, Bahamas, 

 Bermuda : 21 different areas are recognized. 



One would infer from the first sentence of 

 the remarks just quoted that the free-swim- 

 ming larval stage of the Madreporaria has 

 been overlooked. Duerden's " West Indian 

 Madreporarian Polyps " was examined to see 

 if he gives any definite information on the 

 duration of this stage in the corals that he 

 studied. The data given by him are in- 

 definite, but the larvsB of some species may be 

 free for several days at least, and it is possible 

 that those of Siderasirea radians may live in 

 that state for several weeks. Over extensive 

 areas where coral reefs occur, the three condi- 

 tions favorable to the wide distribution of 

 shallow-water coral species are realized; these 

 conditions are : (1) Either shoal water or in- 

 termittent shoals; (2) oceanic currents; (3) 

 larvse that can live unattached for at least 

 moderate, and possibly considerable, periods 

 of time. There is every a priori reason for 

 the relatively extensive distribution of coral 

 species; and it will be impossible to convince 

 many who have had wide experience with 

 these organisms, that their species do not 

 often have such distributions. A few in- 

 stances of wide distributions are Fungia 

 fungiies (L.), from the East Coast of Africa 

 to the Philippines; Fungia paumotensis 

 Stutchb., the Philippines and Papeeti, Tahiti; 

 Fungia patella (Ell. & Sol.), East Africa and 

 the Hawaiian Islands ; Moeandra (Diploria) 

 labyrinthiformis (L.), Bermudas, Bahamas, 

 Belize (British Honduras), Curagao; and 

 there are many other similar instances. As 

 a further illustration, the results recently ob- 

 tained by the reviewer from a study of Or'bi- 

 cella annularis (Ell. & Sol.) and its varia- 

 tions may be cited. The typical form of this 

 species was determined by comparison with 



photographs of the type, kindly furnished by 

 Professor J. Graham Kerr, of the University 

 of Glasgow. The typical form, used in th» 

 most restricted sense possible, of this species 

 is represented in the United States National 

 Museum by specimens from Hog Island, Ba- 

 hamas, Dry Tortugas, Florida, and Belize, 

 British Honduras. One of the variations 

 from the typical form comes from Dry Tor- 

 tugas and Hog Island. The variation from 

 the typical form may be of vegetative origin, 

 i. e., induced by something peculiar in tlie 

 environment under which the specimens lived, 

 or they may be due to variations in the germ 

 cells. We do not know which of these causes 

 is responsible for the variation; but that 

 Orhicella annularis occurs throughout the 

 coral reef areas of the coasts of the Gulf of 

 Mexico and the Caribbean Sea, including the 

 Antilles, Florida and the Bahamas, is un- 

 deniable. The implied postulate • of Mr. Ber- 

 nard that similar forms may have different 

 phylogenies demands stronger proof than his 

 mere suggestion that such may have happened ; 

 for there is no more reason to doubt that in 

 corals morphologic identity means specific 

 identity than there is to doubt its meaning 

 for other groups of organisms. 



As isolation is one of the well-recognized 

 factors in evolution, its influence in the 

 Madreporaria is to be expected, and this ex- 

 pectation is realized. For instance, as the 

 Isthmian region of America has been closed 

 for some time, geologically speaking, diver- 

 gence between the recent Atlantic and Pacific 

 faunas of America is to be expected, and is 

 a fact. 



Mr. Bernard is right in insisting on the need 

 for the experimental cultivation of Madre- 

 poraria in order to understand many problems 

 pertaining to the group ; but we have obtained 

 a number of solid facts without such experi- 

 mentation, and studies of variation and gen- 

 eral ecological investigations are fully as 

 necessary as experiments. 



Ninety-six forms of Porites from the At- 

 lantic Ocean, six fossil forms from Europe, 

 and sixteen recent forms of unknown locality 

 are described. 



From a comparison of the Atlantic and 



