Avuaust 4, 1899.] 
water I collected the soft red mass swim- 
ming on the surface, washed it with distilled 
water and shook it in a mixture of ether 
and absolute alcohol. The red color left 
the soft mass being extracted by the ether. 
The solution of the color in ether did not 
keep the purple tint of the soft mass, but 
showed a fine brownish coloration, the soft 
mass itself appearing now as a gray yel- 
lowish substance, reminding one of blood 
fibrine. It could be reduced to ashes and 
is, therefore, of organic composition. When 
the lake water was directly exposed to the 
mixture of ether and alcohol without hav- 
ing passed through acetic acid no result 
was obtained. Concerning the osmotic 
property of the red organic mass it is to be 
noted that it did not pass through a mem- 
brane of so-called parchment paper, euch as 
is used for covering jars. 
The experiments show that the water of 
the lakes contains an astonishingly great 
quantity of organic red substance and that 
it is this which gives the red color to the 
water. 
The question now arises what the origin 
of the red organic substance is. My sup- 
position is that the substance must be the 
product of bacteria. Each drop of water 
taken from the lakes will be found full of 
them. The bacteria in all the lakes are 
uncolored, but I found that the cocci ex- 
hibit a red color. 
According to ‘ Baedeker’ (Egypt, French 
edition, 1898) there existed another spot in 
Egypt, near Suez, where red salt water is 
found. On page 162 of the guide book I 
read the following note: ‘‘ La coleur rouge 
des marais salants entre des collines des 
Bédouins et le canal, provient d’une petite 
écrevisse (de lVordre des phyllopodes) 
presque microscopique qui y fourmille a cer- 
tains moments. Le matin ils exhalent un 
parfum semblable A celui des violettes.” 
Unfortunately, when I was at Suez I did 
not visit the ‘ marais salants,’ and I, there- 
SCIENCE. 
147 
fore, wish to call this note to the attention 
of the biologists visiting that part of Egypt. 
It would be very interesting to ascertain 
whether the water there contains bacteria 
and the same red organic mass which I 
found in the lakes of the Natroun Valley. 
J. DEewitz. 
SCIENTIFIC BOOKS. 
By A. H. KEANE. 
Cambridge, 
Pp. 184. 
Man: Past and Present. 
Cambridge Geographical Series. 
University Press. 1899. 12mo. 
Plates 12. 
This volume is the sequel to Mr. Keane’s 
‘Ethnology,’ which appeared as the first of the 
series in 1896, and the two must be read to- 
gether. The author has devoted his life to 
ethnology, and he has lived for many years in 
London, surrounded by the best resources of 
libraries, museums and men. Every authority 
worth consulting has been within his reach. 
Mr. Keane is a zealous systematic workman 
and loves his calling. Let us, therefore, hear 
what he has tosay about man, past and present. 
The author is an evolutionist who thinks that 
the genealogy of man is made out. For him 
the ascent of the Hominide is in an independ- 
ent line from some long-extinct, generalized 
form, from which the other families of anthro- 
poidia sprung in independent lines. This pre- 
cursor first appeared in the Indo-Malayan area. 
Indeed, Dubois’s Pithecanthropus erectus is as- 
sumed as typifying nearly enough the first man. 
The time when the precursor became man 
was in the Pliocene Tertiary, and a million years, 
more or less, would suffice for all human his- 
tory. Four sub-species, or varieties of the 
percursor, were developed in as many separate 
areas, namely, Homo Ethiopicus, Homo Mongo- 
licus, Homo Americanus and Homo Caucasicus. 
The centrifugal Pleistocene precursor, erect 
in posture, but not differing greatly from his 
nearest ape-like kin in other respects, physical 
or mental, spread himself over the whole 
habitable globe. In four separate zones, the 
four varieties above named were evolved as 
independently as was the Pleistocene precursor 
himself. This view has led some to rank the 
author with the polygenists, but he denies this 
