l895 . NOTES AND COMMENTS. n 



The name Astvomyelus was instituted by Williamson in 1885 for 

 certain plant fragments which in some respects resembled Catamites, 

 but at the same time showed special characteristics which justified 

 another generic title. A detailed examination of French and English 

 specimens has conclusively proved the organic connection between 

 Catamites and Astvomyelus, and the anatomical characters of the latter 

 appear to be in all respects typical of root structures. In younger 

 examples of the Calamitean roots, alternate strands and primary 

 xylem and phloem have been recognised, and those of the former show 

 the characteristic centripetal development. The secondary wood 

 agrees in structure with that of the stem, and in some cases Cambrian 

 and secondary phloem have been detected. There seems to be some 

 evidence that these adventitious roots of Catamites possessed a double 

 endodermis, such as characterises the roots of EquiseUim. A constant 

 feature of the cortex is its lacunar zone, and immediately internal to 

 the epidermis a protective epidermoidal layer has been made out, thus 

 recalling another feature characteristic of recent roots. 



Fossil Liverworts. 



Fossil remains of cellular plants are rarely discovered, and their 

 reported discovery is generally looked upon with suspicion. This is 

 not surprising, as their soft delicate body, lacking always the core or 

 skeleton of fibrovascular tissue which gives rigidity to the higher plants, 

 and often without even a tough external membrane, is not adapted for 

 preservation. Mr. F. H. Knowlton seems, however, to have got hold 

 of an undoubted Liverwort from the Lower Yellowstone of Montana, 

 which he describes in a recent issue (October, 1894) °f the Bulletin 

 of the Toney Botanical Club. The species, which represents the only 

 extinct form known from North America, is allied to the genus 

 Preissia, and a new genus, Preissites, has been made for its reception. 

 In Europe, if we except some more or less doubtful species of Junger- 

 manniaceae preserved in the Baltic amber, only six fossil species have 

 hitherto been discovered, all of which are closely allied to the recent 

 genus Marchantia. Of the six, five are French, while one from the 

 English Wealden was recently described by Mr. Seward in the 

 British Museum Catalogue of Mesozoic Plants. The American fossil 

 was collected by Professor Lester Ward, to whom the species is 

 dedicated. 



Nuggets of Gold. 



The existence of gold nuggets is a problem which has been 

 debated no less keenly than the existence of sin. Some experts 

 believe in the doctrine of original sin ; Professor Liversidge, of 

 Sydney, who has devoted much attention to the former subject, in- 

 clines to the theory of original gold ; that is to say, he believes 

 nuggets to have been washed out of quartz or calcite veins in which 



