58 TRANSACTIONS AND PROCEEDINGS OF THE [Sess. lv. 



munis, P. Avium, P. Cerasits, P. Padus, Dry as odopetala, 

 Potentilla fragariastrum , Rosa rubyjinosa, Posa canina, 

 Pyrus torminalis, P. Aria, P. Aucupa^ria,, P. communis, P. 

 malus, Cratiegus Oxyacantha, Cotoneaster vulgaris, Pibes 

 Grossukrria, P. alpinwn, P. nigrum, P. rubrum, Hedera Helix, 

 Cornus sangvAnca. 



The continuation of tliis exhibition was postponed to a 

 subsequent meeting of the Society. 



The lantern used in the exhibition had, adapted to its 

 micro-front, the iris-diaphragm referred to by Mr Forgan 

 (see page 53). 



An interesting and exceptional condition in the stem of a 

 plant of Hcdcra Helix was pointed out. In the pith, which 

 normally is composed of uniform cells, a formation of cam- 

 bium had taken place opposite each of the primary vascular 

 bundles, from which a numljer of secondary tissue cells had 

 been cut off. The wood in the vicinity of the pith showed 

 signs of disintegration, and the presence of this adventitious 

 cambium might be attributed to an attempt at the formation 

 of a protective layer. 



An Examination of some Ericas collected by the 

 Scottish Alpine Botanical Club in Connemara during 

 1890. By J. Muirhead Macfarlane, D.Sc, F.E.S.E. 



(With Plate I.) 



During the past year I carefully examined the British 

 Ericas both by naked eye, lens, and microscopically, with 

 the object of determining, if possible, the exact relations 

 of the disputed form E. Mackayi. The interesting finds 

 made by the members of the Scottish Alpine Botanical Club, 

 in the home of the plant have induced me to bring together 

 my observations, and to supplement these by a comparison 

 of known forms with what is undoubtedly a new and striking 

 addition to the list. 



Few plants exhibit less tendency to variation than 

 Heaths, whether in the wild or cultivated state. It there- 

 fore becomes a matter of some importance to note such 

 variations, to attempt to summarize the new features of 

 variation, to record the relative abundance and natural 



