MADREPORARIAN CORALS 69 



Fungia in the same way or, by lateral budding, may give 

 rise to several young Fungias. 



This very remarkable and unique method of reproduc- 

 tion is of very great interest because the detachment of the 

 Anthocyathus from the Trophozooid seems to be a method 

 of reproduction by fission quite unlike the fission seen in 

 other corals. It is not vertical, but horizontal or transverse 

 fission. It is different also from ordinary fission in the 

 respect that the products are unequal and unlike each other. 

 The lateral buds that are formed on the Anthocaulus after 

 the Anthocyathus has broken off seem to be formed by 

 gemmation in the ordinary way ; so that in Fungia we 

 have reproduction by gemmation as well as by this 

 extraordinary method of fission. It is probable that 

 gemmation also occurs in the free adult stages, because, 

 when the under sides of a number of large Fungias are 

 examined, a few young forms are occasionally found at- 

 tached to the thecal walls. This was observed by Ellis, 

 who wrote, " In many curious collections, such as those 

 of the Duchess Dowager of Portland and of Dr. Fothergill, 

 there are many young ones (of Madrepora fungites) ad- 

 hering to the old ones with large rising lamellae as in 

 the old ones." ^ The development of these young ones 

 has recenth' been described by Boschma, who has proved 

 that they are produced by gemmation and not from free 

 larvae. 2 



But that is not the whole story, for in some species, 

 formerly placed in a separate genus Diaseris, the disc- 

 shaped free coral, when it has reached a certain size, divides 

 by vertical fission into four quadrants, and each survives to 

 restore in the course of time by unequal growth the three 

 missing quadrants of its body. 



Fungia has been shown to be a solitary coral, but its 

 corallum has a very similar appearance to the coralla of a 

 series of genera which are really compound corals. 



Halomitra. — The first of this series is the genus Halo- 

 mitra, originally described by Rumphius under the name 



^ Ellis, Zoophytes, p. 153. 

 ^.H. Boschma, Proc. koning'i. Akai. Wet. Amstevdam, xxvi., 1923. 



