104 Clironicles of Science. [Jan,, 



of a corresponding amount of water, as compared with the action of 

 the blue or violet rays, which are the most active in decomposing 

 chloride of silver. 



Y iridescence of heaves. — M. Prillieux has, on the other hand, 

 shown, by a series of experiments on barley, that the production of 

 the green colouring matter of leaves proceeds more rapidly in dif- 

 fused light than in the direct light of the sun, in opposition to the 

 production of oxygen, which is the more abundant the stronger 

 the light. 



Peloria in Lahiatse. — M. J. Peyritsch has presented to the 

 Academy of Sciences at Vienna some remarkable instances of 

 "Peloria," that is, of abnormal regularity in flowers usually 

 irregular, observed in the order Labiatse. They occur in Stachys 

 sylvatica, the common woundwort ; Bdonica officinalis, the common 

 betony; and in seventy individuals of Galeobdolon luteum, the 

 yellow dead-nettle. In the latter instance the flowers are formed by 

 the increase of two segments of the calyx, and by an alteration in the 

 form of the divisions of the upper lip of the corolla, so that they 

 become similar to the lateral lobes of the lower lip. The stamens 

 are perfectly normal, and bear well-developed pollen ; but the 

 carpels are abortive. 



The Leaves of Conifers. — At the meeting of the American 

 Association for the Advancement of Science, held at Chicago, Mr. 

 Thos. Meehan read a paper on the leaves of Coniferse. He pointed 

 out -that the true leaves of Pinus consist of bud-scales; and what 

 are popularly known as the leaves are in reality arrested phylloid 

 shoots. The chief portion of the true leaves in most plants belonging 

 to this order is adnate to the stem ; sometimes they have the power 

 of developing only into scale-points ; sometimes into foliose tips. In 

 Larix the true leaves are linear, spathulate, entirely adnate to the 

 stem. There are two kinds of stem-growth. In one case the axis 

 elongates and forms shoots; in the other, axile development is 

 arrested and spurs are formed. On the elongated shoots the leaves 

 are scattered ; on the spurs they are arranged in whorls. There are 

 therefore in the larch two forms of leaves : the one free, the other 

 adnate. In Cryptomeria the true leaves" adhere for four-fifths of 

 their length on vigorous shoots ; in Juniperus, for nearly their 

 whole length on vigorous shoots ; while on weaker branches they are 

 almost entirely free. In Pinus the phylloid shoots are situated in 

 the axils of the true leaves. Mr. Meehan sums up his observations 

 as follows : — The true leaves of Conifer se are usually adnate to the 

 branches. Adnation is in proportion to the vigour of the genus or 

 species ; or of the individuals in the same species ; or of the branches 

 in the same individual. Many so-called distinct species of Conifer se 

 are probably only varieties of the same species in various states of 

 adnation. 



