44 STEVENSON— INTERRELATIONS OF THE FOSSIL FUELS. 



Friih^* remarks that algse are rare and merely accessory con- 

 stituents of peat, but in some cases they are essential constituents. 

 Alaterial sent to him by F. E. Geinitz from the bottom layer of a 

 moor at Gustrow was, when dry, hard, brown, homogeneous, with 

 a greasy luster on the cut surface. It is laminated, consists in great 

 part of well-preserved Chroococcacese with colonies of other forms 

 of algas, accompanied by pollen of conifers and Corylus as well as by 

 chitinous fragments. He examined Lebertorf from Jakabau, re- 

 ceived from Caspary, in which he found pollen and indeterminate 

 remains of higher plants, embedded in a mass composed chiefly of 

 algae — Chroococcace^e, Hydrodictyse and diatoms. Lebertorf from 

 Doliewen, received from Jentzsch of Konigsberg, resembles the peat- 

 shale or Torfschiefer from Gustrow and contains, along with pollen 

 of Corylus and conifers, well-recognized colonies of Macrocystis as 

 chief constituents. The Purpesseln material is similar in compo- 

 sition. Typical Lebertorf has been found at several places in Swit- 

 zerland, where as elsewhere it consists chiefly of algse, belonging to 

 genera which are gelatinous. Diatomtorf belongs in this group ; he 

 had a specimen from Oldenburg containing 90 per cent, of diatoms. 



Jentzsch^^ states that the Lebertorf of Caspary occurs at many 

 places in Germany. Caspary recognized that it has a granular struc- 

 ture ; V. Giimbel regarded the granules as exceedingly disintegrated 

 plant remains, while Friih believed them to be alg?e. Friih had 

 examined a dried specimen from Doliewen. Jentzsch procured fresh 

 material from that locality and sent it to him. Jentzsch and Cas- 

 pary could find no evidence that Chroococcaceze are present in this 

 substance, structureless granules alone were recognized. All Leber- 

 torfs show as chief constituents these roundish granules, which 

 Caspary, v. Giimbel and Jentzsch regard merely as disintegrated 

 plant material ; associated with these are pollen from Piniis and cat- 

 kins, bits of plant tissue, remains of crustaceans and often, but not 

 always, diatoms and Pediastruui. 



In a note appended to this paper, he gives the substance of a 

 letter received from Friih respecting study of the fresh material 



34 J. J. Friih, " Ueber Torf unci Dopplerit," Trogen, 1883, pp. 20-24. 

 ^^ A. Jentzsch, " Mikrostruktur des Torfs," Schrift. k. ph.-okon. Ges. 

 Konigsberg, Jahrg. 24, 1883, pp. 47-53- 



