NATURAL HISTORY SOCIETY OP GLASGOW. 119 



on the peduncle ; -Ath, closed nectaries ; 5th, temporary closing of 

 the flower ; 6th, inflated calyx ; 7th, diversion of the insects by 

 attractive secretions on part of the plant other than the flower ; 

 8th, position and character of the petals. 



July 15th, 1879. 



Mr. Thomas King in the chair. 



Dr. Stirton exhibited Woodsia hyperborea, and some mosses 

 likely to be found at Blackmount on the occasion of the Society's 

 excursion there ; Mr. Broom exhibited Echium vulgare, Anchusa 

 sempervirens, and tianguisorba officinalis, from the Avon valley, 

 west of Linlithgow; and Mr. Stewart exhibited Lastrea rigida, 

 from Arran — its first discovery in Scotland, also Polystichum 

 angulare, from Arran — its first discovery there. 



Dr. Stirton, F.L.S.. then read a paper on Lichens, in which 

 he showed the relation subsisting between them and the state of 

 the atmosphere. Dr. Stirton stated that, when the environment of 

 Lichens remains unchanged, they naturally live through several 

 centuries, but are so sensitive to any alteration in the amount of 

 moisture or of sunshine that they are easily affected for the worse, 

 and are ultimately destroyed. Hence their great value in register- 

 ing climatal changes. 



July 29th, 1879. 



Mr, W. J. Milligan in the chair. 



Dr. Stirton gave an account of the excursion to Black Mount. 

 The weather was very unfavourable, but several rare plants were 

 found, amongst which might be mentioned Cornus suecica, Pyrola 

 secunda, Lobelia dortmanna, Allosorus crispus, and Gnaphalium 

 supinum. 



Mr. Thomas King then read a paper on "The Development of 

 the Vegetable Ovule from its first appearance till its fertilization." 

 The paper was illustrated by a number of preparations under the 

 microscope, arranged in such a way as to show the progress of 

 development. In a transverse section through the ovary of Loasa 

 the ovules were seen as simple rounded swellings on the three 

 placentas, while those of the Mignonette showed the rudimentary 



