Proceedings of the British Association. 449 



itself with astonishing rapidity. The tree grows on the banks of the 

 rivers Rupununi and Takutu, in the third parallel of north latitude. 



Mr. Schomburgk then communicated a paper, entitled ' Description 

 of Lightia lemniscata, a new genus of the family Buttneriacese. — The 

 Buttneriaceae are very common in Guiana, and in some districts the 

 author met with whole forests of the chocolate nut tree, a plant belong- 

 ing to this family. The Lightia belongs to this family. The great 

 peculiarity of this plant is, that the petals have an elongated appendage, 

 which hangs down from the cluster of flowers, like ribbons, and hence 

 its specific name. This tree attains a height of 20 or 24 feet, and pro- 

 duces its flowers directly from the stem, below the axis of fallen 

 leaves. Only three specimens of this tree were discovered in Guiana 

 by Mr. Schomburgk. 



The last paper by Mr. Schomburgk was ' On two New Species of the 

 family Laurinese, from the forests of Guiana.' — The first is a tree which 

 affords timber which is brought to England, and known by the name 

 of Greenheart. This tree was found, by Dr. Rodie, to possess febrifugal 

 properties, and Dr. Maclagan has published an account of two new alka- 

 loids which he had obtained from it by chemical processes. These 

 alkaloids may be used instead of quinine. The second tree has long 

 been known, and yields an aromatic fruit, known by the name of the 

 Accawai nutmeg, and is extensively used in Guiana as a remedy in 

 diarrhoea, dysentery, and other intestinal diseases. The author suc- 

 ceeded in obtaining flowers and seeds, and had found this tree to be 

 a species of Acrodiclidium, to which he has given the specific name, 

 Camara. It appears to be restricted to the sandstone mountains of 

 Roraima, between the fifth and sixth parallel of north latitude. 



Mr. Schomburgk exhibited dried specimens and drawings of most 

 of the plants he described, as also of the Strychnos toxifera, a plant 

 which produces the true Wouraili poison of Guiana. 



Prof. Balfour stated, that the Greenheart was much used for build- 

 ing vessels on the Clyde. The alkaloid obtained from this tree was 

 called by Dr. Maclagan bibirine, but its insolubility rendered it unfit 

 for medical uses. — Prof. Tilley stated, that although Dr. Maclagan had 

 named two alkaloids as being present in the wood of the greenheart, 

 subsequent experiments had led him to conclude, that there was but 

 one, and this he called bibirine. This alkaloid presented a similar 

 chemical constitution to quinine. It was not, however, combined with 

 an organic acid. 



Mr. Babington then exhibited to the Section specimens of three 

 plants which had been added to the list of British plants during the 



