290 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 



an albino Starling (Sturiius vulgaris, Linn.), the first albino of 

 this species which had come under Mr. M'Culloch's notice during 

 his long experience. 



Mr. Peter Ewing, F.L.S., Vice-President, exhibited some plants 

 collected in Cornwall this year. 



An Alga sent by Mr. Thomas Binnie, Jun., from Lower 

 Kildonan Loch, South XJist, was exhibited and described by Mr. 

 R, D. Wilkie. The identification of the plant as Cladophora 

 cegagropila, Linn., was confirmed by Mr. M. C. Cooke, A.L.S. 

 Cladophora is a genus of green algae of wide distribution, occurring 

 in both salt and fresh water. The body of the plant is filamentous, 

 more or less variously branched, and, in its early stages at least, 

 is attached to the substratum by a basal root-like process. The 

 filaments are septate, each segment containing a dense peripheral 

 layer of small polygonal plates, the chloroplastids, in which may be 

 seen numerous starch granules, and some highly refractive globular 

 bodies termed the pyrenoids. Each segment contains a number 

 of nuclei, so that it must be regarded from a morphological stand- 

 point as being multicellular. Pteproduction is both asexual and 

 sexual. In the former case the contents of a segment, which does 

 not in any way appear to be difi'erentiated from adjacent segments, 

 break up into a number of ciliated masses, which, upon being 

 liberated by the rupture of the cell-wall, swim actively about in 

 the water for a short time, after the expiry of which they fix 

 themselves to the substratum, and bud out into a new plant. 

 Another method of propagation is by the breaking up of the 

 filament into its individual segments, each one of which by apical 

 growth develops into a new filament. Sexual reproduction is by 

 means of ciliated cells which swim about and conjugate, the 

 result of the union being a spore which, upon germination, pro- 

 duces the plant. The sporoph3^te generation is thus seen to be 

 absent. 



The chief interest attaching to this species is its habit of 

 forming large spheroidal masses on the bottoms of the lochs in 

 which it occurs. The explanation appears to be as follows : — 

 When the plant germinates, it is attached to the bottom by the 

 root segment. During growth the filaments branch from centres 

 in every direction, forming, in process of time, a densely felted 

 mass, the meshes of which become infiltrated with fine mud. 



