254 Meyen's Rejiort for 1839 on Physiological Botany. 



which projects out of the earth contains the smallest quan- 

 tity of sugar, but often exhibits a large number of crystals, 

 which are also very commonly found in the leaves of this 

 plant. 



In the report published in Berlin, 1838, p. 21, we an- 

 nounced M. Decaisne's excellent work on the Lardizabalece, 

 which has now appeared*. M. Decaisne speaks at large on 

 the anatomical structure of the stem of the Menispermece and 

 the Aristolochice, in order to show that the arrangement of the 

 natui'al families cannot be effected by means of the structure 

 of the plant. The porous tubes of the ComfercB and Cycadecs 

 have been found in Gnetum and Tasmannia, &c. ; he more- 

 over shows that Prof. Lindley made a great mistake in stating 

 the structures of the Menispermece and AiHs to lochia to be 

 similar, and that the want of zones in the stems vvhich he ex- 

 amined led him to consider the Menisjjermea; as standing in 

 the middle between the Mono- and Dicotyledons. M. Decaisne 

 then describes the structure of the wood of Aristolochia la- 

 biosa, Ar. syjiho, Ar. clematitis -, the latter is exactly similar to 

 the first. He also examined Menispermum canadense and 

 Cocculus lamnfolius, and draws the following conclusions : — 

 1. That the MenisjjermecB are developed diffei'ently from the 

 other Dicotyledons : annual zones are not present ; each lig- 

 neous fascicle remains simple, and the bast when once formed 

 does not visibly enlarge. 2. That the single ligneous fascicle 

 of the Menispermece cannot be compared with those of the 

 Monocotyledons, as is done by Prof. Lindley, for they increase 

 annually, and are placed regularly around the pith ; moreover 

 the bast takes no part in their formation. 3. Some plants, as 

 for instance Cocculus laurifolius and Cissamjjelos Pareira, have 

 a very anomalous structure; and M. Decaisne here describes 

 that of the stem of Cocc, laurifolius, which is quite similar to 

 that of Cissampelos which I have described in my ' Physiology,' 

 vol. i. p. 374. In Cocc. laurifolius, as in the Dicotyledons, 

 a layer of spiral tubes the fibre of which could be unrolled 

 was found only in the first deposit of wood, and close to the 

 pith. Finally, 4. M. Decaisne declares that the Aristolochice 

 cannot, on account of their structure, be so strictly classed 

 with the Menispermece : their ligneous fascicles divide towards 

 the bark ; and the bast, which in a young state forms a circle, 

 divides afterwards into two nearly equal parts, and these di- 

 vide and subdivide again as the diameter of the branch in- 

 creases ; but the bundles of bast always bear a relation to 



* Archives dii Museum d'ilist. Nat., i. Paris, 1839, p. 143. 



