945 



Notice of the ' Reports and Papers on Botany,' published by the May 



Society, 1846. 



The last-published volume of these Reports contains analyses of 

 many valuable and interesting papers on various subjects connected 

 with Botany, both foreign and British, which appeared during the 

 years 1842 and 1843. These are arranged under the heads of " Mor- 

 phology of the Coniferae, by Dr. J. G. Zuccarini ;" " Reports on 

 Botanical Geography, by Prof. Grisebach ;" " Memoir on the Nu- 

 clei, Formation and Growth of Vegetable Cells, by C. Nageli ;" and 

 " Report on the Progress of Physiological Botany, by Dr. H. F. 

 Link." To some of them we may probably revert at a future 

 period; for the present we content ourselves with a few extracts, 

 which we trust will prove acceptable to such of our readers as may 

 not have access to the volume itself. 



On the Excretion of a Fluid from the Apex of the Leaves of Cal- 

 la and Canna. — This phenomenon has already been mentioned in 

 our pages by the late Mr. E. J. Quekett (Phytol. i. 218) and Mr. 

 Wilson {Id. 612); the following observations from the pen of L. 

 F. Gartner are interesting. 



" After an historical introduction follows an accurate diary of this 

 phenomenon in specimens of Calla, which the author had under his 

 eye. He then gives a chemical examination of the distilled fluid, 

 which contains scarcely any solid matter ; the residue after evapo- 

 ration showed principally mucus and hydrochloric acid. Further, 

 with regard to the organization of the leaves, he states, that the ves- 

 sels are not continued to the end of the awl-shaped prolongation at 

 the apex of the leaf, but that here there is nothing but cellular tissue. 

 The secretion takes place at the extreme end of this prolongation, in 

 a length of 1 to 1*5 m. in a scarcely visible manner, until the fluid 

 has collected into a drop. After the death of the prolongation, the 

 margin of the extreme apex of the leaf itself takes on the same func- 

 tion. The special organ of the exudation of the moisture, seems to 

 be the elongated pores of the cuticle ; and the imbibition of the ex- 

 creted fluid, which is sometimes observed, seems also to be owing to 

 the same. Light has no perceptible influence on the dropping from 

 the leaves. Warmth alone has no special action ; though it has 

 when it is combined with immersion in water. The excretion was 

 feeblest in a morning ; increased towards noon ; was most copious in 

 the afternoon, from 2 to 5 p. m., and declined again during the 



