154 THE EVOLUTION OF THE METAZOA 



they had been produced. Thus we get a simple growth cycle 

 by way of an alternation of generations and without a sharp 

 difference between the two generations. 



Subsequent to this we find in a majority of Anthozoa the 

 formation of cormi where the incomplete transverse division 

 developed into longitudinal division and even more so into 

 reproduction by way of buds. The conditions were initially 

 the same as those that can be found in the solitary species 

 that reproduce asexually. There is always a larger number of 

 asexually produced generations. We find occasionally in the 

 formation of cormi that not all asexually produced individuals 

 (they are now subindividuals or persons) become sexually 

 active. In many species of the genus Corallium there are, 

 surprisingly enough, only the changed siphonozooids that 

 become sexually active; the two generations live together as 

 sessile animals in one cormus. 



An interesting and, as it seems, unique case among Anthozoa 

 is represented by Fimgia which has been already mentioned 

 above (Fig. 28). This is an apparently secondarily and not 

 completely solitary madreporarian. Its sexually produced 

 anthopolyp reproduces in two parallel w^ays ; one by w^ay of 

 lateral budding which can lead to the formation of a cormus 

 (colony). In this Fnngia resembles other species of Madrepo- 

 raria. The maternal polyp, however, can reproduce asexually, 

 by way of transverse division; yet this division is unequal. 

 The destiny of the two halves as well as their forms are 

 different. The distal part which is slightly broadened and 

 which takes over the circlet of tentacles and corresponds to 

 the so-called anthocodium of anthopolyps descends, after its 

 separation from the basal part, the former polypid, to the 

 sea bottom. It grows into a large "coral" which continues 

 to lie on its flat side and develops into sexual maturity. Special 

 names have been given to the tw^o generations which have 

 thus been developed by way of transverse division. The basal 

 part has been called an "anthocaulus," and the distal sexually 

 ripe individual an "anthocyathus." There can be no doubt 



