APRIL 12, 1912] 
confectionery or bakery wares will at once 
make the acquaintance of margarine; only the 
preparation of all food in one’s own house in- 
sures safety. Margarine has won this position 
in spite of all compulsory declarations, in 
spite of the foreign-sounding name, because 
it fills the need of the people for a cheap fat. 
Leaving out one recent case where the crim- 
inal negligence of a firm in carelessly selling 
a poisonous foreign fat caused many cases of 
illness and some deaths, so far there has not 
been much with which margarine can be re- 
proached. 
Kk. B. LepmMan 
HYGIENIC INSTITUTE, 
WURZBURG 
SCIENTIFIC BOOKS 
Planktonkunde. Von Dr. Apotr STEUER. 
Leipzig und Berlin, Teubner. 1910. Pp. 
xv-+ 728. Mit 365 Abbildungen im Text 
und 1 Tafel. 
Leitfaden der Planktonkunde. Von Dr. 
AvouF Stever. Leipzig und Berlin, Teub- 
ner. Pp. 882. Mit 279 Abbildungen im 
Text und 1 Tafel. M. 7. Geb. M. 8. 
Many additions have been made to our 
knowledge of the floating life of the sea and 
its counterpart in fresh water, the plankton, 
since Haeckel published his highly theoretical 
“Plankton-Studien ” with its elaborate but 
never generally adopted nomenclature and 
classification of this domain of life. The 
work of the Kiel school and its Plankton Ex- 
pedition and Henson’s Danaid task of taking 
a census of the sea, the Valdivia expedition 
with its superbly illustrated reports, the vari- 
ous expeditions of the Prince of Monaco, of 
the U. S. Steamer Albatross under the direc- 
tion of the late Alexander Agassiz, the work 
of the International Commission for the In- 
vestigation of the Sea and the investigations 
of the fresh-water stations in Denmark, Ger- 
many, Switzerland and the United States 
have resulted in the perfection of instru- 
ments and methods and the accumulation of a 
mass of results. Steuer’s treatise on plank- 
tology thus finds the time opportune for ap- 
pearance and fittingly forms a volume in the 
SCIENCE 
585 
Teubner series (‘“ Naturwissenschaft und 
Technik in Lehre und Forschung”) under 
the editorship of Professors Doflein and 
Fischer, of Munich. 
The first work is comprehensive in plan, 
covering all phases of the varied content of 
the subject of the life of the sea and of fresh 
water. The first chapter of the work deals 
with water, its distribution on the earth, 
chemical constituents, temperature changes, 
its relations to light and pressure, its color 
and odor, and its movements under metero- 
logical influences. Other chapters treat of 
methods, quantitative, qualitative and statis- 
tical, of plankton investigations, of the adap- 
tations of the plankton to flotation with 
special reference to viscosity in relation to 
temperature and season, of adaptations in 
color, and of phosphorescence. 
It appears that the data cited by Steuer are 
quite inadequate to establish his thesis that 
the organisms of the plankton as compared 
with those of the bottom and shore are char- 
acterized by a relatively low rate of reproduc- 
tion. It is not the pelagic nature of the or- 
ganism which is the cause of the low rate of 
reproduction often observed in plankton-poor 
lakes but rather a poverty stricken habitat. 
The herring fisheries, the chalk beds of past 
ages, the abundant and rapidly fluctuating 
plankton of enriched rivers, the occasional 
sudden outbursts of the “mare sporco,” all 
bear indisputable evidence of the capacity of 
pelagic life to respond to opportunities for 
rapid multiplication. This erroneous idea 
that the plankton has a relatively slight ca- 
pacity for reproduction is correlated with 
another all too widely applied idea, namely, 
that the tropical seas are relatively barren. 
The facts are that fresh waters and the sea 
vary greatly in different regions and at differ- 
ent seasons in the amount of life they contain. 
In warm waters the chemical processes of life 
are so accelerated that life cycles are short- 
ened and decay is hastened, while in colder 
waters growth and decay are slower and indi- 
viduals accumulate though the total product 
in the two regions in a given time may be the 
same. Food supply and temperature affect 
