BULLETIN OF TffE UNITED STATES FISH COMMISSION. 2.')9 



ject obliquely inwards and towards the end of the bladder, acts, together 

 with the spring valves at the mouth of the bladder, in utilizing each 

 fresh struggle of the captive for the purpose of pushing it further in- 

 wards. If any of my readers wish tor specimens of this interesting 

 l)lant I shall be enabled in a few days to forward them at a very nom- 

 inal cost. 



Of its destructive powers all I can say is, that out of 150 newly- 

 hatched perch placed in a glass vessel only one or two were alive two 

 days subsequently, and I hope in a few days to be in a position to speak 

 of its powers en natura. 



I must also tender my hearty thanks to Professor Moseley for his un- 

 selfish kindness and courtesy in furnishing? me with notes and all neces- 

 sary information, at a time when his hands are lull with this term's 

 work, and any one who knows rightly the duties of an Oxford professor 

 will agree with me that the position is an arduous one. Such men as 

 Professor Moseley are few and lar between, for, like fishermen, I find 

 that among scientific men there is an amount of jealousy which ought 

 not to exist, and I therefore regard the action of Mr. Moseley in this 

 matter with such feelings of gratitude as are not easily obliterated. 



37 Broad street^ Oxford, England. 



139.— A CARIVITOnOUS I»t,ANT PREYINC OIV VERTETBKATA. 

 By Prof. H. Hi. MOSELEY. 



[From Nature, May 22, 1884.] 



An interesting discovery has been made during the last week by Mr. 

 G. E. Simms, son of a well-known tradesman of Oxford. It is that the 

 bladder-traps of Utricularia vulgaris are capable of catching newly- 

 hatched fish and killing them. Mr. Simms brought to me for examina- 

 tion a specimen of Utricular lava, a glass vessel, in which were numerous 

 young roach newly hatched from a mass of spawn lying at the bottom. 

 ]^umbers of these young fish were seen dead, held fast in the jaws of 

 the bladder-traps of the plant. I had never seen Utricularia before, 

 and am indebted to my colleague, Prof. Burdon Sanderson, for the iden- 

 tification of the plant and a reference to Cohn's research on it. Mr. 

 Simms supplied me with a fresh specimen of Utricularia in a vessel with 

 fresh young fish and spawn, and in about six hours more than a dozen 

 of the fish were found entrapped. Most are caught by the head, and 

 when this is the case the head is usually pushed as far into the bladder 

 as possible till the snout touches its hinder wall. The two dark black 

 eyes of the fish then show out conspicuously through the wall of the 

 bladder. Rarely a specimen is seen caught only by the tip of the snout. 

 By no means a few of the fish are, however, captured by the tail, which 

 is swalli)wed, so to speak, to a greater or less distance, and I have one 

 specimen in which the fish is caught by the yelk sac. Three or four 

 instances were observed in which a fish had its head swallowed by one 



