70 DUBLIN UNIVERSITY 



ON THE OCCURRENCE OF A SINGULARLY METAMORPHOSED STATE OF BRYUM 

 SANGUINEUM ; AND ON THE DISCOVERY OF SOME ADDITIONAL SPECIES TO 

 THE IRISH FLORA. 



It is now a received axiom among botanists, that it is by studying the 

 morphological changes which from time to time take place with phae- 

 nogamic plants, that their true structure can be fully understood. 

 This, no doubt, holds good also to a certain extent with cryptogamic 

 plants, but, owing to the simplicity of their structure, it is rarely that 

 opportunities are afforded for observing such changes of parts, with the 

 exception of Ferns, some of which natural group do occasionally assume 

 appearances differing greatly from their normal state. The Mosses are, 

 however, so constant to their general forms, that they have been likened 

 by some to watch- works among vegetables, in consequence of the regu- 

 larity and fineness of their structure ; any abnormal changes, therefore, 

 found to occur among members of this tribe are the more worthy of 

 being recorded. < 



In the present instance I have to bring under the notice of this As- 

 sociation a remarkable state of Br yum sanguineum, which is so altered 

 in some of its parts as to render it unlike the typical state of the plant. 

 In the normal form of this species the lids of the capsules are shortly 

 apiculate, i. e. they have short points, whereas the changed states here 

 exhibited have long rostrate beaks, nearly equalling the length of the 

 capsules themselves. Besides, these beaks are swollen at their bases in 

 such a manner as to appear as if considerable progress were made in the 

 formation of a second capsule, articulating with the first ; and in one 

 specimen there is no lid whatever, but a gradual tapering of the appa- 

 rent capsule from the base to the long-pointed apex. The whole plant 

 is more or less altered, the leaves being narrower and more lanceolate 

 than they usually are ; and in one case two of the seta) were observed 

 joined together nearly their whole length, when they separated towards 

 their apices, each ending in a regular capsule. Mr. Wilson, to whom 

 I sent specimens of this monstrosity, considers that the change arises 

 from a morbid incorporation of the calyptra with the operculum when 

 in an early state of inflorescence. This I also believe to be the prin- 

 cipal cause, though it will not fully account for the plant which has 

 no operculum. The specimens here presented were found growing in 



