574 Reviews — W. Carruthers on the Fossil Cycadece. 



quainted with the real characters, not only of many already de- 

 scribed, but of others subsequently discovered. 



Among those who have specially devoted themselves in this country 

 to this subject, we may cite the names of Hooker, King, Williamson, 

 Binney, as well as of the author of the paper before us, whose name 

 has now become familiar to the readers of this Magazine by his 

 frequent contributions to its pages.^ 



Mr. Carruthers, like Dr. Hooker, has brought to bear upon fossil 

 forms an extensive knowledge of recent plants, both structural and 

 physiological, which gives to his published opinions considerable 

 weight when treating of the relics of vegetable remains found im- 

 bedded in the various strata. 



So frequently indeed do the remains of plants occur in a frag- 

 mentary state (from which fragments sometimes species, and even 

 genera, have been made almost at random), and considering also 

 how commonly the more important parts by which plants can be 

 identified are wanting in the fossil state, — as, for instance, flowers 

 and fruits, — or, if found, are frequently dissociated from each other ; 

 it requires all the skill and special knowledge, derived from the 

 study of recent Botany, generally to allocate and rearrange the 

 scattered fragments and determine their true affinities. 



This method of investigation is thoroughly carried out in the 

 Monograph before us, "On the Fossil Cycadean Stems from the 

 Secondary Eocks of Britain." 



The recent Cycadem are a peculiar and interesting group of 

 Gymnospermatous plants which from their organs of fructification 

 are related to Goniferae, and in their habit of growth present some- 

 what the aspect of Palms. As a group, they are restricted to the 

 Asiatic, to the African, to some part of the Australian, and to the 

 American Continent. 



The fossil remains of 'this family are chiefly confined to the 

 Mesozoic strata, in which their remains are both abundant and 

 characteristic, for their stems, leaves, and fruit are so perfectly pre- 

 served that their true nature can be determined with the utmost 

 precision. 



Most of the organisms in the Palseozoic rocks referred to this 

 group are either difficult to determine, or belong to other plants. 

 " The detached fruits present no characters justifying their reference 

 to Cycadem. The stems from the Coal-measures, figured and 

 described by Presl under the names of Cycadites columnaris, C. 

 involutus, and Zamites Cordai, are certainly arborescent cryptogams 

 belonging to the same group as Lepidodendron, as Brongniart and 

 Miquel have already shown." (p. 675.) 



Other Palgeozoic genera which have been referred to Cycads also 

 belong to the Cryptogams. Thus Mr. Carruthers observes : — " The 

 structure of Medullosa, Cotta, and Colpoxylon, Brong., referred by 

 Goppert, Miquel, and linger, to Cycadece, diifers so essentially from 

 any known stem of that order, that I would even go further than 



^ No fewer than sixteen papers by Mr. Carruthers on Fossil Botany (besides eight 

 on other subjects) will be found in the pages of this Journal. 



