Current Literature . 
34 
made to a seed-like condition, is full of interest. It would almost 
seem indicated in this case that it may be possible to correlate the 
effect of season and environment upon the nascent structure with 
the degree of similitude to a seed attained. Whatever the fossils 
may tell us, and they are astonishingly instructive at times, it must 
be remembered that we are far from having extracted all possible 
information from plants still living. The realisation of the hope of 
morphologists that we may ultimately possess a complete chain of 
data shewing the lines along which seeds have been evolved may be 
remote, but for all that it seems well in sight. That Lcpidocarpoii 
will play a part in the solution of this question there can be little 
doubt. F. W. O. 
NOTES ON CURRENT LITERATURE. 
Marine Bacteria and their Activity. 
I T is well known, from the observations of Fischer, that Bacteria 
are found distributed generally in the sea, but of the part 
that they play in the general “economy” of the ocean we have 
very little knowledge. There is a special need for information as to 
the metabolism of the marine bacteria. In connection with this 
point Beijerinck has studied a small number of the luminous 
bacteria of the sea, and Russell has shown that certain aerobic 
bacteria from the Atlantic sea-bottom are able to reduce nitrates 
to nitrites, but in spite of these researches we are entirely 
ignorant as to the “circulation of nitrogen” in the sea. We have 
no information as to whether a process of nitrification takes place 
in the ocean at all, or even if there exist marine organisms which 
are capable of fixing free Nitrogen; and as to the opposite process of 
denitrification, it has not hitherto been clear that this process 
could be carried on by the common non-luminous bacteria of the 
sea, or that bacteria found there conditions suitable for this process. 
In a recent paper—“Studien liber Meeresbakterien. I. Reduc¬ 
tion von Nitraten und Nitriten,” von H. H. Gran : Bergen’s 
Museums, Aarbog, 1901, No. 10—the author has investigated the 
power of denitrification possessed by bacteria collected from the 
surface of the North Sea, off the coast of Holland, and also the 
conditions under which the process takes place. The species 
commonly met with seemed to be more than twenty in number, 
