natural history society of glasgow. 107 



February 28th, 1865. 



Jolm Scouler, M.D., LL.D., F.L.S., President, in the chair. 

 The following gentlemen were elected resident members: — Messrs 

 William Lorrain, James Eobertson, James Brown, and James 

 Stirton, M.D.; and Mr Adam Sutherland, Irvine Academy, 

 corresponding. 



SPECIMENS EXHIBITED. 



Mr Alexander M'Kinlay exhibited an abnormal form of Breutelia 

 arcuata, with two sessile capsules on one seta, and of Atrichum 

 xindulatum, with the calyptra attached to the seta. . He remarked 

 that abnormalities of any kind seemed to be of rare occurrence 

 among mosses, and among the lower Cryjitoganis generally, the 

 comparative simplicity of their structure not admitting of much 

 variety of modification; whereas, among the more specialized 

 forms of Cryptogamic plants — such as ferns — and among flowering 

 plants, many interesting and instructive anomalies were frequently 

 displayed. 



Berkeley, in his " Introduction to Cryptogamic Botany," does 

 not mention any abnormal forms whatever among mosses; but 

 Hofmeister (" On the Higher Cryi^togams," Ray Society, p. 181), 

 quoting Bruch, who details the observations of Giimbel, records 

 several instances of abnormal fructification. 



Of the two additional instances brought forward by Mr 

 M'Kinlay, the first, Breutelia arcuata, with two sessile capsules on 

 one seta, is, in the meantime, chiefly interesting on account of the 

 apparent rarity of the occurrence. Hofmeister records a similar 

 one in Milium serratum, and the deduction he draws from it is, 

 that such occurrences " seem to indicate the possibility of a bifur- 

 cation of the growing upper end of the fruit rudiment." Mr 

 M'Kinlay expressed the opinion that two sessile capsules on the 

 same seta is simply a more developed form of two stalked capsules 

 on one seta, the union being only of greater degree in the one 

 than in the other. The union of two seta may be considered some- 

 what analogous to, though, of course, in origin widely different 

 from, the union of two stems in flowering plants, and in such cases 

 the common stem is invariably more or less flattened out. It is not 

 stated that any peculiarity of that kind was observed in Giimbel's 

 " double fruits." In the present instance, however, the seta 

 carrying the two capsules is obviously thicker than that on the 



