MICROPALÆONTOLOGY OF POSTGLACIAL DEPOSITS. 495 
In striking contrast to this spectrum is No. 14 from North-East Sjælland ; 
it, too, shows a subatlantic spectrum. It is based upon the diagrams given 
by Jessen (1920) from Sekkedam, Warming’s Mose, and Maglemose. The 
only feature in common with the diagram from Sebastiansberger Heide is 
the large percentage of Fagus and the small percentage of the mixed oak 
forest. 
6. SUGGESTIONS FOR A PROGRAMME FOR FURTHER INVESTIGATIONS, 
Great Britain and Ireland offer a large and advantageous field for 
continued researches in the statistical method. In his ‘Origin of the British 
Flora, C. Reid has collected the facts as to pre-, inter-, and post-glacial 
floras published before the year 1900. Although much more information 
has been accumulated during the last twenty-five years, many problems, 
especially those relating to the age of deposits, still remain unsolved (ef. 
Bennie, 1891, the Redhall flora from a section described by Henderson in 
1874 and many others). 
A comparison is greatly to be desired between the micropalæontology of the 
interglacial beds of Great Britain and those of Middle and Eastern Europe. 
These latter have, especially as to macro-fossils, yielded much of great 
importance. Quite recently A. Kozlowska (1923) has discovered (at Rakow, 
Poland) wood-remains which can hardly belong to any other species than 
Tsuga canadensis. Pollen-diagrams from such places would be of much 
value for the comparison of deposits. 
Pollen-spectra from the spruce-bearing strata of the Cromer Forest Bed 
might be of special interest (cf. C. Reid, 1880, 1900, 1913 ; C. and E. M. 
Reid, 1907-1909). 
By the use of the statistical method in a more or less modified form, we 
might also study material older than these late Pliocene strata, e.g. the 
brown coal, from which Giimbel (1883) in an extensive paper has described 
and figured pollen which occurred abundantly ; also epidermal fragments 
of grasses, conifer needles, diatoms, spiculæ of Spongille, ete. Cf. also 
Bertrand (1913). 
Gümbel (l. e.) and Reinsch (several papers, 1881-1883), and most recently 
Turner and Randell (1923), have also given an account of the micropalæon- 
tology of coal from Trias, Dyas, Permian, and Carboniferous strata, Reinsch 
has described under the collective name Trilites small bodies closely resem- 
bling Sphagnum spores. That these sometimes occur in extraordinary 
profusion appears from the following passage from a paper of 1887:— 
** Mehrere dieser 7v»ilites-Formen im Russischen Carbon finden sich in solch 
enormer Menge, dass man den Antheil dieser mikroskopischen Körper an 
der Substanz wohl zu 80-90 per cent. annehmen kann. Von der erdigen 
und Torbanitähnlichen Steinkohle von der Pruckscha Guvern. Nowgorod 
wird ein Cubikcentimeter ungeführ 5,827,000 einzelne 7rilites-körper von 
durchschmittlich 0:033 mm. diam. enthalten." 
