Morphology of the Madreporaria. 385 



Thus all the researches on the asexual reproduction of 

 corals go to prove that polyps arising as buds reproduce all 

 the characteristics of polyps formed directly from larvEe. 

 Excepting the peculiarities dependent upon the colonial state 

 I know of no feature by which bud polyps can be distinguished 

 from larval polyps. The polyps arising on a colony as buds 

 are to all intents and purposes new individuals, as much as 

 polyps reared directly from larvse. 



Another group of West-Indian corals includes such genera 

 as Favia, Dichocoenia, Isophijllia, Manicina *, Mceandrina *, 

 Pecti?iia, and Colpophyllia, all of wiiich reproduce asexually 

 by fission, not by gemmation. The characteristics of these 

 will now be compared with those of the gemmiferous polyps 

 given above. 



Numerous decalcified polyps or parts of the polypal 

 system of species belonging to each genus have been studied 

 anatomically, and beyond the early developmental stages all 

 agree in the following features: — (a) absence of directive 

 mesenteries ; (h) absence of any hexameral or other regular 

 cyclical plan. As such studies involve the prolonged process 

 of decalcification and the preparation of numerous microscopic 

 sections, it has not been found possible, except in colonies of 

 Manicina and Favia, to investigate the entire polypal system 

 of any large colony ; but the number of typical regions 

 examined in each species appears sufficient to warrant the 

 summary just made. 



The calcareous septa in the genera mentioned confirm the 

 results from the mesenteries as to the absence of any hexameral 

 cyclical regularity. While frequently three or four different 

 sizes o£ septa may alternate in a manner which suggests so 

 many different cycles, the regularity of the grouping is never 

 continued beyond a very short distance; other septa are 

 intercalated or some are wanting, and thus the apparent 

 normal sequence is destroyed. Of all the species studied the 

 corallites of Favia fragum present the nearest approacli to 

 individuality, but in scarcely any two of these is the number 

 of septa the same, and there is no suggestion whatever of 

 hexamerism. Tlie septa may present an approximation to 

 a tricyclic condition, but such is never maintained all the 

 way round the corallite !• 



* Verrill (1001, p. 6G) has united these two genera along with Diploria 

 and Caloria under the genus Mceandra of Oken, 1815. 



t "Where collections of actual specimens are not available the very- 

 fine series of photograpliic reproductions of West-Indian corals in the 

 recent papers of Vaughan (1901) and Verrill (1901) serve suiHciently well 

 to show the essential ditlerences in the characters of the septal systems of 

 gemmiferous and fissiparous corals. 



