NATURAL HISTORY SOCIETY OF GLASGOW. 167 



The Secretary remarked that since the time of Aristotle the 

 fact of female birds assuming the plumage of the male bird had 

 been well known, and that the recorded instances had chiefly 

 occurred among the gallinaceous birds. Mr Gray also stated that 

 this change would, in all likelihood, be observed in other families 

 of the feathered tribes, if proper attention were directed to the 

 subject. 



Mr George J. Combe exhibited a very beautiful and interesting 

 collection of hardy ferns, principally from the lake district. The 

 collection embraced specimens of Athyrium filix-fcem. var. Vidorice; 

 Lasfrea thylepteris; L. f. m. remota, L. Barnes'd; Scolopendrium 

 vulgare, var. excurrens, etc., on all of which Mr Combe made some 

 remarks. 



Mr Alexander M'Kinlay exhibited specimens of a lichen, 

 Thelopsis rubella, and of a moss, Andrecea alpesiris, both new to 

 Britain, having been gathered by himself in the West of Scotland. 



PAPERS READ. 



I. — Notes of Geological Exmrsions to the Bathgate District. 

 By Mr John Young. 



Mr Young referred to the Boghead cannel coal, which he 

 considered as only a local variety, and pointed out the changes 

 it undergoes in its mineral composition as it passes out of 

 the district, becoming the middle slaty blackband ironstone 

 of the Lanarkshire coalfield. He likewise remarked that it 

 could be nearly matched in all its important characters by other 

 varieties of cannel now known to exist in our Scottish coalfield — 

 the amount of hydro-carbon which they contain being only one of 

 degree, and even this is shown to be variable in the Boghead coal 

 itself. Mr Young next referred to the richly fossiliferous lime- 

 stones of the Bathgate hills, and noticed the important lessons 

 which the student of geology might learn from the careful study 

 of the organic remains in the limestone strata, which are 

 associated with volcanic ash and other interbedded trap rocks. 

 He also indicated the relation which the Bathgate limestone holds 

 to other strata of the same nature in the Lanarkshire and Ayr- 

 shire coalfield, and stated his belief tliat the thick-bedded lime- 

 stones of the district around Beith in Ayrshire, and of Corriebum 

 on the Campsie hills, belong to the same geologic period, as is 

 indeed evident from the organic remains of the strata. 



