202 
sponges, etc.). On these mother-coralla with strongly worn-oft 
surfaces buds are often found whose anthocaulus is provided with 
a ring indicating the place where a former anthocyathus has detached 
itself from it. A new anthocyathus is then usually developing itself 
above this ring. In the largest attached anthocyathus four complete 
cycles of septa have developed (fig. 54). It has a diameter of 5 
mm but it is probable that normally the anthocyathi attain a larger 
size before becoming free. These larger anthocyathi have already 
a hexagonal shape. Another noticeable faet is that the buds of this 
species as compared with those of F. hexagonalis, which possess 
the same number of septa, have on the whole a mueh more solid 
appearance, the stalk also being mueh thicker. 
In the specimen of the fig. 51 also some marginal buds have 
developed. 
Some of the buds have abnormally developed in one direction 
and in these there are occasionally two mouths. Macroscopically 
it is not easy to determine whether these abnormities are the 
result of fission of one polyp into two halves or the result of 
coalescence of two buds that have originated beside each other. 
A microscopical series of one of these enlarged buds shows two 
separated stomodaea, each of which has two pairs of directive 
mesenteries. Now Duerden (1902) has shown that the Cardinal 
difference between fission and budding is found in the directive 
mesenteries: in cases of budding the new individual develops two 
pairs of new directives, whilst in processes of fission in all the 
polyps of the colony there are only two pairs of directives, viz. 
those of the original coral-polyp. In the case described here therefore 
the abnormal bud cannot have got its enlarged form by fission but 
it must have developed from two buds that have united. It is also 
possible, but less probable, that the original bud divided into halves 
by budding and that afterwards these secondary buds had coalesced, 
by which process the occurrence of the double sets of directives 
may be also explained. 
