6 YORKSHIRE NATURALISTS UNION. 



It is impossible to find a permanently moist situation in 

 which algae are absent. They are found on damp earth, rocks, 

 walls, palings, shaded tree-trunks, in spouts, rain-tubs, etc. ; 

 they are met with again in all kinds of running water, from the 

 tumbling cataract and rapid torrent to the slow, majestic river ; 

 but it is in perfectly quiet waters 'that they are most prolific, 

 whether it be in the tiny moor-pool or the expansive lake. 

 Some even find shelter in symbiotic relationship with other 

 plants; for instance, a species of Anakena lives with the aquatic 

 I.ycopod Azolla, and another lives with the Hepatic Blasia, to 

 say nothing of those associated with fungi to form the com- 

 pound dual organism known as a lichen, or those symbioticallj- 

 connected with such animals as Hydra viridis and certain species 

 of Amoeba. 



Many of the larger freshwater algse are noticeable as green, 

 slimy masses floating on the surface of or attached to the sides 

 of ponds, ditches, rivers, etc. Small tufts of these are best col- 

 lected in tubes or small bottles. Constantly dripping rocks yield 

 quite characteristic species, and even shady, moist rocks have 

 an alga-flora of their own. On vertical, moist rocks (especially 

 limestone) it is not uncommon to find coriaceous patches, or 

 gelatinous masses, of a red, brown, green, bluish-green or 

 blackish colour, and an examination of such masses is always 

 interesting. 



There are a vast number of beautiful algse which are very 

 minute, and the places in which they abound are not usually 

 obvious to the casual observer. They generally occur about the 

 stems and leaves of submerged plants, such as Ulricularia 

 minor, Myriophyllum, Nymphcea, Nuphar, Potamogeton, Sdrpus 

 fluitans, Iso'etes, etc. Many of the Muscinese, such as Sphagnum 

 fontortu/ii, S. plumosum, Amblystegium scorpioides, A.fakatum, 

 A. exanniiliitum, A. glaucum, Fontinalis antipyretica, Junger- 

 mannia inflata, Nardia emarginata, etc., are often richly clothed 

 with small species. The best way to collect from plants of this 

 kind is to remove them (or portions of them) from the water with 



Trans. Y.N.U., 1896 (pub. Aug. 1900). Bot. Series, Vol. 5. 



