308 Review of the 



REVIEWS. 



Art. T. Remarks on the JVatural Order Cycaddcerp^ u-ith a 

 description of the Ovula and Seeds of Cycas revoluta. By 

 A. J. Downing. Read before the Lyceum of Natural His- 

 tory, New York, and published in Sillima)i''s Journal for 

 April and May. 



This is an exceedingly interesting and well written paper, 

 upon a subject very little understood, viz. the germination of the 

 Cycadaceae, and formation of the seeds of the plants of this or- 

 der. The various species flower so rarely that botanists have 

 not had an opportunity to study the character of the order, and 

 as yet the structure of the plants remains but partially known. 

 This paper contains an account of the observations made by 

 Mr. Downing upon a fine specimen of Cycas revoluta, which 

 was produced last season in the garden of Mr. Knevels, of New- 

 burgh, New York, upon a plant about thirty years old, which 

 had flowered once previously. It is accompanied by a lithogra- 

 phic folio plate, which is necessary to the proper understanding 

 of the description, and the reader who is desirous of seeing this 

 paper entire we refer to Dr. Silliman's Journal, The prefatory 

 remarks upon the order we copy, as exhibiting a brief account 

 of all the observations that have been made upon it, by those 

 botanists who have examined the plants. 



" For a long time, those who examined this group of plants seom to 

 have lieen more occujned with their external appearance, as exhibited 

 ill the fine pinnated foliage and simjjle trunk of Cycas, than with any 

 minute investigation of the real nature of the reproductive organs. 

 When, however, the plants of this order were attentively examined as 

 to their germination, their mode of inflorescence, and especially as to 

 the nature of those singular bodies denominated the female flowers, 

 new light was throwTi upon their characters and affinities. To that 

 learned and most accurate botanist, Robert Brown, we are mainly in- 

 debted for those views which explain the true structure of Cycadaceae, 

 and establish an intimate relationship with the apparently very different 

 group of plants known under the name of Coniferee. These views 

 were presented to the world in a paper read before the Linnaean Society 

 of London, in 1825, on the 'structure of the female flowers in Cyca- 

 daceae and Coniferae.'* The elder Richard, in his admirable ^ Mimoire 

 sur les Coniferes et les Cycadees,' prepared about the same time, and 

 published afterwards by his son, had indeed, with great ingenuity, es- 

 tablished the affinity between Cycadaceaj and Coniferae; but his views 

 respecting the female flower and seed of both these tribes difl"er widely 

 from those of Brown, and are now generally admitted by the first bota- 

 nists to be erroneous. The female flower of these orders consists, ac- 



* " Vide Appendix to Capt. King's Voyage, p. 22." 



