2 Weiss, A/irn Aquatic Plants iii tJie Reddish Canal. 



and has greatly interfered with the fishing in some 

 locahties. One of the notable and interesting cases of 

 the establishment of alien aquatics in the Manchester 

 district, has been the (occurrence of several plants from 

 Southern Kurope, in a portion of the Reddish Canal, 

 where the temperature is more o\ less permanently raised 

 by the inflow of heated water from several Cotton Mills 

 along its banks. The two best known of these aliens, are 

 Naias grauiinca (Del.) var Delilci (Magnus) and Cliara 

 Brannii (Gmel.), were first reported as occurring in a 

 natural state in ICngland, at the meeting of the British 

 Association in Southport in 1883, and owe their discovery 

 to Mr. John Whitehead of Dukinfield. An excellent 

 account of Naias gi-aiiiinca, and of its occurrence in 

 Lancashire, together with an attempt to settle the manner 

 of its introduction into this country, was given by 

 * Mr. Charles Bailey in \\-\q. Journal of Botany, in 1884. 

 Naias grauiinca is not a native European plant, though it 

 has been found in some stations in the plains of 

 Lombardy, where according to Italian botanists it has 

 been introduced with East Indian Rice, which is cultivated 

 in Northern Italy. Mr. Bailey, however, came to the 

 conclusion that the seeds were not brought into Lancashire 

 from these European stations, but probably with bales of 

 Egyptian cotton, which is used in one of the mills, whence 

 the seeds were transported with the refuse from the 

 blowing and carding rooms into the canal. This is 

 rendered all the more probable by the fact that the variety 

 o{ Naias graniinca, named Delilci hy Dr. Magnusf occurs 



* Charles Bailey. " Notes 011 the struclure, the occurrence in Lanca- 

 shire, and the source of origin of A^a /'as graniinea Del." loitrjial of Bofatty, 

 vol 22, nos. 262 and 263, 1884. 



t Magnus 1*. " Uber eine hesondere geographische \'arietiil Atx Na;as 

 ^raniinea Del. und deren Auftiett-n in I-2ngland." Bti: ner litutscli. Bol. 

 Geselt, 18S3. 



