256 Chronicles of Science. [April, 



flowering plants peculiar to the island. No woods are now to be 

 found in the country, although some existed recently; the trees 

 were all birch ; nor is there any trace of the former existence of 

 pines, or of any other kind of forest-tree ; extensive woods of dwarf 

 birch-trees are found in several parts, and some shrubby willows. 

 No grain of any kind is grown on the island. The north-west 

 corner, which has been comparatively little visited, appears to enjoy 

 the least inhospitable climate. 



Flora of Bound Island, Mauritius. — At the meeting of the 

 Linnean Society, held March 3rd, Dr. J. D. Hooker read a very 

 interesting letter from Sir Henry Barkly, Governor of Mauritius, 

 on the flora of this very little-known dependency of the colony. 

 The island is about 25 miles from Port St. Louis, and only about 

 3 miles in circumference and 1 J mile across ; but its flora differs 

 from that of the Mauritius, not only in species, but also in genera 

 and even in families, although the depth of the intervening sea is 

 only 400 feet. The island consists of a mound of tuff about 1000 

 feet in height, but without any apparent crater, bare of vegetation 

 in the lower part. Only about twenty-four species of flowering 

 plants were gathered during the visit, of which more than one-half 

 are not found in the Mauritius, including three species of palm, one 

 of them 30 or 40 feet high, a Pandanus or screw-pine, and two 

 species of ebony. The fauna is equally peculiar. 



Movements of Chlorophyll. — A very interesting series of obser- 

 vations has been made by the French botanists, Prillieux, Kose, and 

 Brongniart, on the apparently spontaneous movements within the 

 leaves of plants of the grains of chlorophyll which constitute the 

 green colouring matter. These grains had been noticed by previous 

 observers to congregate under the direct action of light. M. Pril- 

 lieux performed his experiments on a species of moss, a kind of plant 

 which offers great facility for these observations, as the movements 

 can be observed in them under the microscope without dissection, 

 owing to their transparency. When the moss had been kept in the 

 dark for some days, the cells presented the appearance of a green 

 network, between the meshes of which was a clear transparent 

 ground. All the grains of chlorophyll were attached to the walls 

 which separate the cells from one another ; there were none on the 

 upper or under walls which form the surfaces of the leaf. Under 

 the influence of light the grains change their position from the 

 lateral to the superficial walls, the movement taking place, under 

 favourable circumstances, in about a quarter of an hour. On attain- 

 ing their new position, the grains do not remain entirely immovable, 

 but continually approach and separate from one another. If again 

 darkened, they leave their new position, and return to the lateral 

 walls. Artificial light produces the same effect as daylight. A 

 protoplasmic material is intimately associated with the grains of 



