xxiv] WATER-FOWL AND WATER PLANTS 299 



An interesting experiment in the colonisation of a pond was 

 made at Garstang in Lancashire some years ago 1 . The pond in 

 question was dug in a grass field and carefully railed off to 

 prevent access of cattle. After about eighteen months certain 

 aquatic Angiosperms had appeared in the pond Alisma 

 Plantago, Callitriche and Glyceria fluita ns, as well as species of 

 Juncus. In the course of the next five years no new hydrophytes 

 appeared, but Alisma, Glyceria and Juncus conglomerates deve- 

 loped so freely as practically to exclude any intruders. In con- 

 nexion with the Garstang experiment, it is significant that 

 fragments of Alisma Plantago, Glyceria fluitans and Juncus sp. 

 were observed by a French botanist 2 many years ago attached 

 to the feet and feathers of migrating birds. The only water birds, 

 actually seen to visit the Garstang pond, were Moorhens, but 

 other aquatic species were numerous in the district. 



That water birds convey hydrophytes from place to place, 

 is so far an accepted fact that it has been stated that it is "vain 

 to make a shallow reservoir in the line of the constant migration 

 of water fowl (i.e. between their resorts), and expect it to main- 

 tain a freedom from water plants 3 ." On the other hand we 

 occasionally meet with an apparent exception. A case was re- 

 corded in Germany 4 in which Utricularia Eremii grew in one 

 locality, while in another, less than a mile away, U. minor was 

 found. These marshes had been under observation for a century, 

 and, during that time, no exchange of species had taken place, 

 though, throughout the summer, numbers of Ducks and other 

 water-fowl flew daily between the localities in question. 



There is obviously no doubt that hydrophytes and water-fowl 

 are constantly brought into intimate relations. One has only to 

 watch Moorhens in summer, running for long distances over 

 Waterlily leaves without wetting their feet, to realise that plant 



1 Wheldon, J. A. and Wilson, A. (1907). Information relating to 

 this experiment has been most kindly supplied to me by letter by the 

 authors, to supplement that recorded in their Flora of West Lancashire, 



2 Duval-Jouve, J. (i 864). 3 West, G. (i 9 1 o). 

 4 Meister, F. (1900). 



