Prince. — Inimical Animals and Conditions 61 



the young fish seems to be smoking a pipe. Little by 

 little the prey is swallowed and disappears." 



I have seen young fish, one -fifth of an inch long, swal- 

 lowing Copepods more than half their own length, and 

 the antennae and swimming feet could be observed pro- 

 truding for some time from the mouth of the devourer, 

 On the principle of lex talionis, the Copepods make war 

 upon the larval fishes, though probably only upon those 

 that are weak and in a moribund condition. It is true 

 that I noticed a bright green Copepod in Irish waters 

 over 20 years ago that seemed to attack floating eggs; 

 but I had not the time or opportunity to ascertain to 

 what extent this might be the case. On numerous occa- 

 sions, however, I have found Temora, Calanus, Oithona 

 and other species of Copepods, abundant in New Bruns- 

 wick waters, making short work of dead larvae of vari- 

 ous fishes. So rapidly do these minute crustaceans do 

 their destructive work that unless minute organisms, 

 removed from the townet, are placed in preservatives, 

 only small fragments will remain, especially of young 

 fishes. I have not actually seen Copepods attack living 

 fish-larvae of the minute types occuring in the surface 

 waters of the sea. 



MEDUSAE AND OTHER JELLYFISH KILL FISH LARVAE, ETC. 



There is, however, clear 'evidence of the destruction 

 worked by certain jellyfish. Professor Mcintosh, of St. 

 Andrews, Scotland, long ago described and figured a 

 Ctenophore, Pleurobrachia, swimming downwards in the 

 sea and engulfing a larval crab (in the zoea stage) and 

 later in his book, jointly issued by Dr. Masterman and 

 himself, he gave a figure of a Ctenophore which had 

 captured a larval fish, whose head protuded from the 

 mouth or manubrial aperture, though the body and tail 

 were partly digested. 



In 1888 Professor Mcintosh described a small medusa 

 (Thaumantias) as most predaceous and so "greedy that 

 it engulfs post-larval fishes and thus it is necessary to 

 remove them from contact with the Cydippes at the 



