270 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 



Mr. David Bruce exhibited a stuifed specimen of an Albino 

 Common Cormorant, Phalacrocorax carbo, L., shot on Loch Roag. 

 He detailed a former hunt he had had for a specimen of this 

 bird, in the course of which he observed that the wings were not 

 used for propulsion when swimming, and when expanded serve 

 only for purposes of balance. 



Mr. John Lindsay, M.A., M.B., CM., showed specimens of 

 Supernumerary Digits, to illustrate the 1 2th chapter of Darwin's 

 " Variation of Animals and Plants under Domestication." Of 

 special intei-est was the foot of a Horse, which, by the presence of 

 an extra toe, revealed reversion to the type of Hipparion, a long 

 extinct ancestor of the Horse. With regard to the explanation 

 generally of extra fingers and toes. Dr. Lindsay demurred to Dar- 

 win's suggestion that these were due to reversion to a lower type. 



On behalf of Mr. M'CuUoch, taxidermist, there was exhibited 

 a Grey-hen from Islay, assuming the plumage of the Blackcock. 

 The neck and shoulders of the bird were blue ; the back several 

 shades darker than is usual in the Grey-hen ; the tail almost 

 black ; under tail coverts white ; and it had also white shoulder 

 spots. Such birds are generally known to be barren, but the 

 owner of this specimen believed it to be the same as one 

 frequently observed at the same place with a young brood. 



Mr. Alex. Patience exhibited about twenty-four specimens of 

 the Higher Crustacea from the Pirth of Clyde, and a few other 

 marine forms In his remarks he dealt with the phenomenon 

 known as commensalism, illustrated by the dwelling together of 

 the Hermit-crab, Eiqmgurus prideauxi (Leach), with the Sea 

 anemone, Adamsia j)Miata (Bohad.) ; and of the Hermit-crab, 

 Uupagurus puhescens (Kr.), with the Sponge {Suberites suberea, 

 Gray), and which receives as a boarder a small segmented worm, 

 which acts the part of a scavenger. Mr. Patience also gave some 

 notable instances of Parasitism, e.g., Sacculina carcini (Thomp.), 

 on the abdomen of the Shore-Crab, Carchius mcenas (Penn.); 

 Chondr acanthus lophii, Johnst., from the gill-pouches of the 

 Angler-fish (^Lophms piscatorius, Jj.); Lernceahranchialis, L., from 

 the gills of whiting ; and the Isopods, Pseudione affinis, G. O. 

 Sars, and Phryxus abdominalis (Kr.), the former from the gill 

 chambers, and the latter from the abdominal cavity of the shrimp, 

 Pandalus montagiii, Leach. The phenomenon of "masking" 



