142 



Dr. J. E. Duerden on the 



of whicli can be found on almost any stock and must lie 

 regarded as abiioinuJities." Also, Prof, A. H. Veirill (1901, 

 p. 9(i), in desciibiiig (JihiceVn ncroj'ira (E!l.& Sol.), siiitply 

 statt's : — ''lliis sj)ecies occasionally shows cert;;iii caliclcs 

 larger than usual, and with more septa. Such calicles may 

 subdivide by regular fission, as is the ca«e with the similar 

 nnufually large cells in some species of Porites, Mddrcp'jra, 

 Pocilioj.ora, (^c, in which fission is elsewhere very unu-uul." 



An anatomical study of many enlarged j)olyps of this 

 character, found on various West-Indian corals, has revealed 

 ceitain morphological facts bearing upon the more general 

 subject of asexual reproJnction in corals. 



In a farmer paper (1J)02), I liave fully described the 

 peculiar nietiiod of growth of the enlarged polyps in the 



A B C D C BA 



Transverse section through the stomodfeal region of an enlarged, lioral 

 polyp of Madrepom vnn-tcata, Linn. Two slomodiC;i o'ccur, each 

 Aviih the nie.^eiueries anaigcd as in an i.rdiiiaiy >iniple pilvp of 

 Madrejn.ra. The pinii.iy tix paiis o! uietenteiits are indicated 



the lioiran nunierali: 

 mesenteries 111. A aiv 



1- J J, iinu the six later } aii s hy the letters A-I 

 nd IV, E on each side are directives. 



by 



porose genera Acropora {Madrepora) and Ponies, and have 

 shown how the piocess of simple tissiun there takes place. 

 Ihe figure of a section cf a double \io\y^ oi Madrepura is 

 a^ain introduced, to illustrate the conditions under which the 

 phenomenon occurs in that genus (rig. 1). In the stages 



