LIFE AND WRITINGS OF >T. DE MARTIUS. 7 



vestigation. The second chapter, by M. Unger, is upon Fossil Palms ; 

 and in the third Martins takes up the pen and pursues the subject to 

 the close, by describing the formation of the various organs, from the 

 root to the inflorescence and fruit. In discussing the stem, M. Mold's 

 remarks are confirmed ; while the convolution and display of the fibres, 

 combined with the leaves, to which they extend, are treated in a tho- 

 roughly scientific and masterly style. Various tables of figures exhibit 

 the rate of increase in the trunks of several kinds, both in height and 

 girth, the annual number of their leaves, and the distance between 



these leaves. It is the opinion of M. de Martius, that the uubranched 

 Palms, in general, do not attain a great age, — not more than three 

 centuries : while Dicotyledonous trees occasionally live for thousands 

 of years, and die by accident. The ramified Palms, such as the Doum 

 of Egypt, which is almost the only instance of this growth among the 

 Tribe, are probably much longer-lived than the others, and this seems 

 only natural, as each branch issues from a new bud ; while, in the 

 normal state of these trees, the same terminal shoot is continued and 

 becomes exhausted as it rises farther and farther from the roots. 



The formation of leaves, and their relative arrangements, are carefully 

 treated ; and numerous observations exhibit the varieties which take 

 place in each species. In most botanical treatises it is customary to 

 judge of the foliage and its arrangement by the examination of one 

 part of a stem ; while M. de Martius asserts that the Date Palm has all 

 the following dispositions of the leaves : — \, ■§-, ^-, -£% ; the Chamcedorea 

 Schiedeana f , |, etc. Again, the arrangement of the floral leaves, termed 

 spathas, often varies ; and it differs from that of common foliage, ad- 

 hering however to the mathematical rule of the spiral, as the above-men- 

 tioned figures plainly prove. The parts of the flower are equally closely 

 studied. In all these respects, the work in question is on a level with 

 the most recent observations ; though the plates in the first volume 

 have been published these many years. The development of the whorls 

 of flowers in the Palms is normal, — that is, from the exterior to the 

 interior; still, the three ovules precede the ovaries, which is not an 

 unimportant fact, whether in itself, or as bearing on the theory of the 

 origin of ovules. As for the relative situation of the floral parts, and 

 of the bracteas or bractlets which surround it : the subject is one in 

 which M. de Martius delights, and of which he gives numerous figures 

 and details in this work, unequalled, I believe, by any Monograph. 



