Geology and Natural History. 501 



one or more members of the amphibole, augite or mica families 

 present, and not according to the crystallographic nature of the 

 essential feldspar, the name proposed seems hardly necessary. 



l. v. p. 



6. The Gems and Precious Stones of North America ; by 

 George F. Kunz. — An Appendix to this fine work, making pages 

 337-367, has recently been issued. It gives much interesting 

 matter, supplementary to the main volume, chiefly that which 

 mineralogical investigation has brought out in the past two years. 



7. Mucrferous System of Laminariacem, by G-uignard (An- 

 nales des Sciences Naturelles, 15, I). — This study proves that 

 certain genera of Laminariaceai, such as Lessonia and Alaria, 

 can comprise species which have no muciferous canals, while others 

 possess them. We therefore must conclude that their presence 

 or absence cannot offer any specific character. g. l. g. 



8. Researches on Multiple Buds, by W. Russell (Annales 

 des Sciences Naturelles). — The principal conclusions which these 

 researches have led the author to are : 



(1) Lateral buds can be produced at the expense of the con- 

 stituent parts of the foliar axil, either at the expense of the stem 

 alone, or more rarely, that of the leaf. In the inflorescence of the 

 Linden, Cactaceas, and so on, their appearance can take place upon 

 the summit at the same time as that of the axillary leaf. 



(2) Every bud has at the commencement a double growth, — 

 a proper growth, or one peculiar to itself, and a growth in com- 

 mon with the organs which have formed it. The latter is in gen- 

 eral much more rapid than the former, at least at the outset. 



(3) The majority of leafy buds, and numerous flower-buds, can 

 send out branches at their base. 



(4) These buds are the origin of successive ramifications which 

 accompany the bud of the first generation, and sometimes these 

 possess no axillary leaves at all. 



(5) These successive ramifications, which are ordinarily desig- 

 nated as accessory buds or multiple buds, behave at the outset 

 just as axillary buds themselves. 



(6) The disposition of these buds always obeys the laws of 

 phyllotaxy. 



(7) The basal ramifications have a well-defined biological role. 

 It is from- these that many thorns and tendrils are produced, or 

 modifications of inflorescence. 



(8) In the majority of cases these buds remain in the state of 

 dormant buds, and are the origin of distortions which appear 

 under certain circumstances in woody plants. Sometimes upon 

 annuals they play the role of hibernating buds, and permit the 

 plant to grow from one year to another. They can develop in 

 the same year that they form, or in the following year, coinci- 

 dental with the bud of the first generation. 



(9) We can show experimentally that the formation of these 

 buds can continue throughout the whole life of the plant. This 

 is well illustrated by Convolvulus, for example. 



