6 RKCKNT MADREI'ORARIA OK THE HAWAIIAN ISLANDS AND l.AYSAN. 



"variety "' is used in the sigiiilicaiico usiuilly attiihutcd to it in Airicrica. A " variety" 

 would 1)0 a secondary mode on a species curve. Th(\ de Vries " vari(>ty" should be 

 a retroi.'-rade "spoeies."' Mr. Gardiner, in speakin<;- of Fiiiu/in deiithjeni as probably 

 being a "true variety,"" uiisappiies the de Vries term "" \•ari(^ty." Fintgia denflgtjra 

 differs from F. .scuiaria by the possession of strongly developed tentacular lobes. 

 These tentacular lobes arc an added, not a retrogressive character; therefore in the 

 de \'rics sense F. di/it/'r/cru can not be a "variety." If F. Nnitariii has lost its 

 tentacular lobes it might be a "variety" of /'. (Jfiiligi'vu. Later, it is shown that 

 F". dentigerii and F. .scutaria are connected by continuous variations. 



Porites cmnjyrema and Poritea hihata are di\ided into numei'ous ^\fon)iw'" and 

 "■ sithyonnx.^^ The variations recorded have ))ecn ol)served, and it is believed that 

 they should be described and figured, but their oi'igin is not known. It is not known 

 whether they are of gametic or vegetative origin. Some of tiiem may be of specific 

 value, but tiie conformity to a type is so closelj^ followed throughout all of them and 

 there is so nnicli observable intergradation that I fancy they all intergrade. 



Throughout this paper, however, I h:ive striven earnestly to make clear what 

 forms, even down to minor \ariations, ha\'c been studied, so that the nomenclature 

 ma}' be considered of minor importance, 'i'he descriptions are usually elaborate, 

 many statistical tables are gi\-en, and the illustrations are profuse. 



NEED OF EXPERIMENTAL INVESTIGATION AND MORE ELABORATE STUDIES 



OF VARIATION IN CORALS. 



Studies of variations, such as those contained in this paper, may appear elal)orate 

 to persons wiio have not gone deeply into the sul)iect, but in reality they are of only 

 a preliminary nature, for as stated in the introductory remarks "there is on every 

 side an insufficiency of data," and consequently it is not possible to solve many of 

 the fundamental prolilems pertaining to the group. The study of variation is 

 in.separal)le from experimental physiological investigations, for these are a necessary 

 foundation for the understanding of variation. 



Mr. .I.Stjudey (iardiner divides variation in the Madreporaria into three classes: 

 (a) Ckmtiu lions, {\i) viyeiative, and (c) dlncontuiuom or specific.'' 1 think two kinds 

 should be recognized: (a) Gametic, (b) vegetMlve. Oametic variation is due to dif- 

 ferences in the ])ai-ental gametes, and, should tlie de Vi-ies nuxtation hypothesis be 

 correct, it should be, divided into contuiuuufs and dixcuntlnnoas. Vegetative variation 

 is due to the effect produced upon the organism by the environment under which 

 it lives. 



Variation in the Madreporaria should be studied in three ways: (1) In nature 

 without e.xperiment; {^l) in nature by experiment; (3) under artificial conditions in 

 aquaria. 



1. In nature without experimetit.—Conx\ fields, according to this method, should 

 be ecologically suiv(\ved. l'lu> study of specimens of the same species obtained 

 under the same pliysical conditions would give information on gametic variation, 

 while the comparative study of specimens belonging to the same species, oi)tained 



« Madreporaria, l-'auna and Geography of tlie Maldive and Laoeadive Archipelagoes, II, p. 9:59. 

 >> Idem, p. 7.5.5. 



