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II. 



PRELIMINARY NOTES ON THE CARBOHYDRATES OF THE 



MUSCI. 



By THOMAS G. MASON, BA., Diplom. Agpjc, TOD. 



[COMMUNICATED BY PROFESSOR HENRY H. DIXON, SC.D., F.R.S.] 

 [Read November 23, 1915. Published Februakv 17, 1916.] 



The wide divergence of opinion that prevails concerning the carbohydrates 

 of the angiosperms has suggested that an investigation conducted among the 

 Musci would be of great interest, and might shed light on the subject of 

 photosynthesis. The work was undertaken early in January, 1914 ; owing 

 to the war, however, it was found necessary to discontinue it ; yet, incomplete 

 as it is, it seemed advisable to place on record the experiments which had 

 been already completed. 



The Musci chosen for investigation were — 



Polytrichum commune. 

 Thuidium tamariscinum. 

 Sphagnum cymbifolium. 



The material has been collected among the hills and woods of the counties 

 Dublin and Wicklow, and the experiments have been carried out in the 

 Botanical Laboratory, Trinity College, Dublin. 



Brown and Morris (2), who worked on the leaves of Tropaeolum, arrived 

 at the following conclusions : — 



1. Cane-sugar is the first sugar synthesised by the assimilatory process, 



and is the starting-point of all the metabolic changes taking place 

 in the leaf. 



2. When the degree of concentration of the sucrose exceeds a certain 



amount, starch commences to be elaborated by the ehloroplasts. 



3. Sucrose is inverted, and starch converted into maltose before 



translocation. 



It may be pointed out, however, that their experiments do not exclude 



SCIENT. PBOC. K.D.S., VOL. XV., NO. II. C 



