xxx proceedings of the 



24th May, 1887. 



Dr. James Stirton, F.L.S., President, in the Chair. 

 Mr. David Gregorson, F.E.I.S., reported on an excursion made 

 to Milngavie on 21st inst.* 



Mr. Thomas King, Vice-President, referred to the loss which the 

 society had recently sustained in the death of Mr. Thomas Ballantyne, 

 one of the Ordinary Members. 



The President exhibited specimens of Barbula convoluta, Hedw., 

 in fine fruit, from Bridge of Weir, and remarked that although the 

 moss is exceedingly common in a barren state, it is not very often 

 found with well-developed capsules. He also showed specimens of 

 Pilophoron fibula, Tuck., from the same district, and of Grimmia 

 Stirtoni, Schpr., from Glen Ogle, Perthshire. 



Mr. D. A. Boyd exhibited fruiting specimens of Mnium hornum, 

 L., having the calyptra attached to the seta immediately below the 

 capsule. He stated that instances of a similarly abnormal position 

 of the calyptra in Atrichum nndulatum, L., had formerly been 

 brought before the society by Mr. Alexander M'Kinlay.f In that 

 case, however, the shape of the capsule was apparently affected 

 by the position of the calyptra, as it was described as short, ap- 

 proaching an ovate form as in A. tenet lum, and with a much shorter 

 lid than usual. In reference to this point Mr. M'Kinlay, when 

 exhibiting the specimens of J., tuiduhitum, had stated that although 

 the calyptra not infrequently takes up this abnormal position, he 

 was astonished at the altered shape of the capsule, and sug- 

 gested the following explanation of its change of form: " Can 

 it be that the peculiar shape of the capsule is dependent on the 

 peculiar position of the calyptra ? Not improbably it is so, 

 seeing we find the same correlation of growth existing in speci- 

 mens from different localities. What more likely than that the 

 calyptra in its normal position, by covering the nascent capsule and 

 thus protecting it from various adverse circumstances, should exercise 

 a beneficial influence on its growth into the normal shape. Such I 

 take to be the function of the calyptra, and to the absence of it in 

 its proper position may be attributed the abnormal shape of the 

 capsules in question." In accordance with this view, however, we 

 should expect to find a similar modification in the shape of capsules 

 of M. hornum which had not had the protective covering of the 

 calyptra ; but as these did not appear to differ either in size or 



*See Transactions, vol. ii., p. 322. t Proceedings (First Series), vol. i., p. 108. 



