Plant Distribution and Basic Ratios. 271 
abundant fat, and these, as far as my observations go, are 
characteristic of calcareous water. 
In the case of the Diatoms and Ceratium — calcium salts 
in the external solution seem to be necessary in order to form 
the fat impregnated walls (of insoluble calcium soaps) found 
in these organisms. The scarcity of fats in the algae of waters 
containing principally potassium and sodium may be due to 
the loss of these fats as soluble potassium and sodium soaps 
by diffusion into the water. The calcareous lakes are usually 
characterised by a deficiency of oxygen in their deeper layers, 
and the presence of fats in the Diatoms and Ceratium (which 
pass at least part of their existence in these deeper layers) 
seems to imply, as in the case of the peat plants, the possibility 
of respiration without oxygen. 
When growing plankton algae in dilute culture solutions, 
it was found that the solutions containing a high basic ratio 
apparently prevented not only the predominance of diatoms, 
but also largely inhibited the growth of fungi. If generally 
the case, this might explain the scarcity of fungi in sour soils, 
and since the fungi are responsible for the decay of organic 
matter, it would lead indirectly to the accumulation of peat 
in such soils. The observation might help to explain not 
only the antiseptic properties of these soils, but also the fact 
that organic matter decays very slowly in waters containing 
high basic ratios. Certainly in the English lakes, with waters 
of this type, little fungal and bacterial action exists in deep 
water, and consequently oxygen is not used up — and the deeper 
waters remain well aerated. In these lakes where the waters 
have a low basic ratio there is abundant organic decomposition 
in deep water, the dissolved oxygen is used up, and the carbon 
dioxide freed causes these deeper waters to become acid. 
These changes affect not only the phytoplankton, but also the 
fishes and other animals inhabiting such a lake. 
According to the press, Mr. H. D. Roberts, of Brighton, states that 
the importance of Natural History is now recognised in the schools and 
other institutions throughout the country ! 
‘ Bacteria ’ is the main theme in Part 16 of The Outline of Science. 
It is written by Sir E. Ray Lankester, ‘ the greatest living zoologist . . . 
the Achilles of Darwin,’ a coloured portrait of whom appears in the part 
and also on the cover. 
We learn from the fourth annual report of the Gilbert White Fellowship 
that there are now 324 members. ‘ The Gilbert White Memorial Fund 
makes but slow progress. During the year the subscriptions received 
have been few, and the total fund, after the deduction of expenses, stands 
at less than ^30.’ 
The second edition of ‘ A Handbook to the Collections illustrating 
a Survey of the Animal Kingdom ’ has been issued by The Horniman 
Museum (66 pp., 6d.). It contains a detailed account of the natural 
history specimens in the collections and an appendix on ‘ Hints on the 
Study of Zoology.’ 
1922 Aug.-Sopt. 
