/•r Natural History, 437 



the disappearance of the insects, does not require more than a quar- 

 ter of an hour. The youni^ larvae reach the earth) qiid< (then pene- 

 trate downwards. — Bw//. C/ntr. Bw XX. 181. -^ .;i^(jr»<i 



8. .^j^^o/X^:ft/o»P2ir/i<f;' MvLeaohdi-^^-^'iswdl kabwnthat 

 solar li^ht, by enabling plants to decompose and assimilate carbonic 

 acid, gives them the power of forming volatile and aromatic princi^ 

 pies, and of acquiring a green colour. Its presence ife so Necessary 

 to flowering and frubtification, that ripe seeds have never been ob- 

 tained in darkness ; on the contrary, if an etiolated plant be exposed 

 for three, four, or five hours to the sun, it immediately becomes of 

 an equally intense green colour, with those which have continually 

 grown in light. Plants raised in the open air, when put into dark- 

 ness, become pale and fade in two or three days ; those which, after 

 being raised in darkness, have been exposed for a time to sunhght, 

 cannot again support the privation of light, but die; and water 

 charged with camphor, or essential oil, which has great power of 

 invigorating plants, cannot prevent their destruction. The perfect 

 absence of light is therefore very injurious to plants, andM. Leuchs 

 concludes, that, without the light of the moon and stars, nights 

 would destroy vegetables. r! , >; . >.;.,,, m!! . 



The light of a lamp can, although imperfectly, replace that of the 

 sun, the plant becomes green and tends to the light. When seeds 

 were germinated in three vessels, the first uncovered, the second 

 covered with single, and the third with double paper, those of the 

 first vessels exhibited less external development, but when dried, 

 they gave more solid matter ; those in the second were more deve- 

 loped, but were more aqueous and loose ; the difference was still 

 greater in the third vessel. 



The texture of various plants appears to be more or less aqueous 

 (if the word may be used), when deprived of light according to the 

 nature of the plants. When plants were placed in a damp cellar or 

 cave, enlightened by a flame, those nearest the flame contained 

 most solid matter ; the results were so regular, as to present some- 

 thing like a law, relative to the action of various quantities of light 

 on vegetables. r . . . . . . ^ ; 



Light reflected by mirrors appeared to have b very beneficial in- 

 fluence upon plants, andM. Leuchs' thinks that many hill sides are 

 rendered fertile by the similar reverberation of hght from the neigh- 

 bouring rocks. — Archiv von Kastner, xv. 



II 0. 0» the Size of the Pear and other Fruits i M. Jaume St. Hi- 

 laire. — M. Saint Hilaire observed in certain wall pear trees that the 

 fruit which was supported on the branches or otherwise, grew to a 

 larger size than that which hung freely in the air, and thought that 

 the difference probably arose from the weight of the hanging fruit 

 stretching the vessels in the stalk, and therefore, by contracting their 

 diameters, rendering them less able to convey that abundance of 

 nourishment which they might otherwise receive. In consequence of 



