4 GEOLOGICAL MEMOIRS. 



dried up. But, on the other hand, there are wanthig many of those 

 criteria of extinct volcanic action which would lead me to lean with 

 confidence to the side of an igneous origin ; for with the exception of 

 the few loose fragments of a hasaltic rock, I miss every product of 

 extinct or active volcanos ; I see no lava, not one of the so-called plu- 

 tonic rocks. I miss a distinct undoubted crater, all lava-streams, &c. ; 

 in short, the agreement with any one of the volcanos I have since seen, 

 either in respect of the nature of the rocks or the structure of the soil ; 

 in fine, of the w^hole habitus. Are the appearances to be explained 

 by supposing the rocks to have been altered by hot vapours ? by the 

 action of some principle similar to that which in the island of Milo 

 has changed clay into porcelain jasper ? 



" I believe that I ought to call upon every geological traveller who 

 visits the land of the pyramids not to omit to visit Dschebel Achmar. 

 As far as I know, I am the first who has examined it with reference 

 to science ; but I am by no means convinced, and I say so with perfect 

 sincerity, of the soundness of my conclusions ; and of this he will be 

 able to judge, who, free from prejudice, will investigate the phseno- 

 mena on the spot." 



Cont7'ibutions to the Flora of the Broivn-Coal Formation. 

 By Prof. GoppERT. 



[From Arbeiten der Schlesischen Gesellscli. 1847, p. 74.] 



In the year 1839 I examined some of the bituminous wood found in 

 the brown-coal formation in various districts of Northern Germany *, 

 and at that time described two species (Pinites Protolarix and Tax- 

 it es Ayckii)^ which, from the width of their distribution, seemed to 

 me peculiarly deserving of attention. More recently, in the work 

 published conjointly with Dr. Berendt in Danzig, on the vegetable 

 remains found in amber, I collected a flora, comprising fifty-four 

 species, which in regard to the genera could not be distinguished 

 from that of the brown-coal ; although no brown-coal beds contain- 

 ing amber in its natural position have yet been certainly pointed out. 

 The amber which I formerly thought I had discovered in the brown- 

 coal at Muskau is nothing more than Retinasphalt. I now possess a 

 small stem covered with the bark, on which the resinous exudation 

 appears in drops, and many other fossil coniferse, among them even 

 Taxineae, show the same appearance, but none of them, so far as I 

 know, such an abundance of resin as the small stems and the frag- 

 ments of wood in my collection which produced the amber. These I 

 have figured and described in the work mentioned above, and they 

 have been seen by a great number both of German and foreign natu- 

 ralists. At present they must be regarded as the only remains which 

 give us any certain knowledge of the existence of at least one tree 

 producing amber, although I have no doubt that there were several. 



* See a paper ' On the bituminous and petrified wood recently discovered in the 

 basaltic tufa of the high Seelbachkopfe near Siegen, with remarks on the brown- 

 coal formation generally,' in Karsten and v. Deeheu's Archiv, vol. xiv. p. 182 etc. 



