106 ANNALS OF SCOTTISH NATURAL HISTORY 



alike as to their power of preying upon insects, more than 

 usual interest has been excited in regard to them. Several 

 of the plants that formed the subjects of Darwin's experiments 

 belong to comparatively common species, such as Utricularia 

 vulgaris, Drosera rotundifolia, and Pingnicula vulgaris ; and 

 this no doubt has tended still further to increase the interest 

 in the peculiar and remarkable habits possessed by such 

 plants. 



Utricularia vulgaris is an aquatic plant, and in the 

 Edinburgh District occurs in moderate abundance in pools 

 at Gullane Links, near Aberlady. The utricles of this species 

 are large and numerous, and very frequently contain micro- 

 organisms that have found their way into what has proved to 

 them a living tomb. 



Many years ago I examined a number of utricles of 

 another species Utricularia minor discovered in pools by 

 the side of the road between Port Glasgow and Kilmalcolm 

 (west of Scotland) ; and a Note of the organisms observed in 

 the utricles was published in the " Greenock Telegraph " ; 

 but for various reasons I had not till lately the privilege of 

 examining the much larger and finer Utricularia vulgaris. 

 During the month of May last year my son, Mr. Andrew 

 Scott, and I made a partial investigation of the locality about 

 Gullane and Aberlady and collected some specimens of 

 Utricularia vulgaris, which were placed in spirit till a con- 

 venient opportunity occurred to look over them. A con- 

 siderable number of the utricles on these specimens have 

 now been examined, and the following is a record of some of 

 the results obtained. 



In the first place, I examined five hundred utricles, none 

 of them being smaller than about the one-twelfth of an inch 

 across the longest diameter. They were taken from the 

 plants indiscriminately, except as regards size, and their 

 contents were carefully investigated and recorded. Of the 

 500 utricles, Si were empty, that is, they did not contain 

 organic matter ; 3 5 contained organic matter, but so much 

 decomposed as to be indistinguishable ; while 384 contained 

 organic matter that could be identified. 



Of the 384 utricles containing matter that could be 

 identified 



