64 PRACTICAL CARP CULTURE. 



aquarium, where I have also a large number of newly-hatched perch and 

 roach, a novel and unexpected enemy to the pisciculturist in the bladder 

 traps of Utricularia vulgaris, which is capable of catching and killing 

 young fry. 



1 My attention was first drawn to it by observing that several of the 

 tiny fish, without any apparent cause, were lying dead on the weeds, 

 while the rest of the brood looked perfectly healthy and in good condi- 

 tion. At first I was somewhat puzzled at the strange position in which 

 they were lying, and in trying to move one with a small twig I was still 

 more surprised to find it was held fast by the head, in what I thought 

 when I pulled the plant from the water, were the seed vessels ; and a still, 

 closer examination revealed the strange fact that others of the little fish 

 had been trapped by the tail, and in one or two instances the head and 

 tail of the same fish had been swallowed by adjacent bladders, thus form- 

 ing with its body a connecting bar between the two. 



At first I was undecided how to act, for I could bring to memory no 

 instance in which I had seen the existence of a piscivorous plant /. e., 

 one preying on vertebrates recorded in any book I had ever read, and 1 

 was unwilling to make an assertion without the opinion of some one 

 better capable of forming a judgment on the subject than myself ; so I 

 placed one or two good specimens in a glass jar and went to the Museum, 

 where I was fortunate enough to see professor Moseley, who immediately 

 verified my suspicions. 



According to Bentham's Handbook of British Flowering Plants, the 

 Utricularia vulgaris, or greater bladder wort, is widely distributed over 

 Britain, and although it is local, yet where it is found it grows luxuri- 

 antly, seldom appearing in the rivers, but chiefly confining its presence 

 to still ponds and deep ditches, the places where it is most likely to work 

 mischief to the young fry. A peculiar fact in connection with it is that 

 it has no roots at any time of its life, and the floating, root-like branches 

 which are covered with numerous capillary and much divided leaves are 

 interspersed with tiny green vesicles, which were supposed by a former 

 school of botanists to be filled with water, by which means the plant was 

 kept at the bottom until the time of flowering, when the water gave place 

 to air, and the plant then rose to the surface to allow its bloom to expand. 



As a matter of fact, the vesicles exercised no such function, their real 

 work being to entrap minute crustaceans, worms, larvae, &c., for its sup- 

 port, and without a good supply of which it is impossible to keep it alive 

 in an aquarium. 



This form is that of a flattened ovoid sac, or, in other words, when 

 seen under a low-power microscope, they are precisely like a human 

 stomach, and they are attached to their hinder extremities each by a 

 very short and fine pedicle or foot-stalk in the axle of the leaves. 



Each, too, has an opening at the opposite free extremity, somewhat 

 quadrangular in outline, from either side of which project two branched 

 processes, called by Mr. Darwin antennae. 



