230 BULLETIN OF THE BUREAU OF FISHERIES. 



More recently Nutting has suggested the ingenious view that phosphorescence may 

 sen-e as a lure, attracting copepods and various larvae within reach of the luminous 

 organism. "The process would be analogous, perhaps, to what is known as the effect 

 of alluring coloration among insects and birds. The phosphorescence would thus be of 

 direct utility to the fixed ccelenterates in securing food." Unfortunately, there is no 

 more evidence in support of this than in that of Prof. Verrill. And on the other hand, 

 there is much which goes to show that such a view is directly in conflict with too large 

 a mass of facts to render it at all probable. Such are the facts of phosphorescence in 

 littoral forms, and in free-swimming and surface forms, whose modes of taking prey 

 render it highly improbable that they have any need of such an aid. Phosphorescence is 

 not solely a property of deep-sea life nor of nocturnal feeders. The writer regards it as 

 associated with processes of metabolism; and while not beyond the realm of utility to 

 the organism it is not directly so. Theories dealing with the subject have been pro- 

 pounded on the assumption that every vital feature and phenomenon must be brought 

 into aligfnment with natural selection. It is to be hoped that we are emerging from the 

 shadow of that assumption. 



REPRODUCTION. 



Generation in this class, as in others of the phylum, is both sexual and asexual, 

 though without the more or less rhythmic alternation of generations so characteristic of 

 the Hvdrozoa. The sexual products are borne on certain of the mesenteries, and when 

 ripe are usually extruded through the mouth. In some species, however, development 

 may take place within the mesenterial chambers, and the young later discharged in a 

 fully formed condition. The sexes are usually distinct, as in most Hydrozoa, but may 

 be united in a single individual in certain species. That is, Anthozoa may be either 

 dioecious or moncecious — unisexual or bisexual. Duerden has shown (1904), in the 

 case of certain corals, that the bisexual or hermaphrodite condition may prevail, a given 

 individual producing both ova and sperms, though not at the same time. That is, the 

 genital products mature at somewhat different intervals, the organism being protogynous, 

 maturing the ova first; or it may be protandrous, maturing the sperms first. 



Asexual propagation is of general occurrence and of great importance. It is chiefly 

 by the process of budding; though fission is not unknown among actinians, a given 

 specimen dividing longitudinally, much as in Vorticella. Parker (1897, Bulletin of Museum 

 of Comparative Zoology, p. 43) has described this process in Metridium marginatum, 

 and Torrey has shown the same in the case of M. fimbriatum (Proceedings California 

 Academy of Sciences, vol. i, p. 345, 1898). The writer has observed the entire process take 

 place in Sagartia htcun, a small but extremely interesting anemone of our coast. In this 

 species fission is apparently a common feature of reproduction. In text figure i is shown 

 a sketch of a Metridium in process of fission. Such specimens are not particularly rare. 

 Still another mode of asexual reproduction is more or less familiar, namely, that known 

 as fragmentation. It consists of the formation of numerous minute individuals by 

 a sort of indefinite budding from the margins of the pedal disk. This process seems 



