May 23, Tyi2| 
NATURE 
307 
sickle-shaped bodies were present in the red corpuscles. 
These bodies could not be found in the blood of this 
child on the following day, but there occurred, in 
the plasma, ovoid bodies, which, according to Prof. 
Hlava, were similar to Leishmania. In the accom- 
panying figure, however, only a single nucleus is 
shown in each cell, whereas two nuclei are present in 
Leishmania. 
J. Horej$i (Bull. Internat. Acad. Sci., Prague, xv. 
Ann.) records observations on the symbiotic union of 
a cyanophycean alga (Anabzena) with the roots of 
Cycas_ revoluta. 
through the lenticel-system, passes into the meri- 
stematic apical tissue, retarding the activity of the 
latter, inducing dichotomy and the eventual produc- 
tion upon the root of a coral-like outgrowth. The 
advantages to the two organisms concerned are prob- 
ably mutual; the root derives from the alga its nitro- 
genous products, whereas the alga takes up from the 
root a certain part of its host’s products of assimila- 
tion. In the same bulletin Dr. B. Nemec traces the 
stages of degeneration of the nuclei in the cells which | 
form the sieve-tubes in Euphorbia, Ricinus, &c. 
The biology and physiology of a species of dodder | 
(Cuscuta gronowii), parasitic on willows, have been 
investigated by Dr. K. Spisar (Bull. Internat. Acad. 
Sci., Prague, xv. Ann.). He found that seedlings 
would wind round organic or inorganic supports of 
varying thickness, the contact-stimulus being very 
strong, contact with a suspended thread being 
sufficient to bring about the reaction. The zone in 
which the response reaches its maximum is in or 
near the growing zone. During the formation of 
haustoria, which is not dependent either on light or 
on the want of food, growth ceases, and the circum- | 
nutation movements are lost, but reappear in two or 
three days. This dodder is not very fastidious in 
regard to its host, and may even be “parasitic”? on 
itself. The tissues remaining in the haustorial zone, 
when the rest of the dodder has been torn off its 
host, give rise to adventitious buds, and thus re- 
generate the parasite. The purple-red colour depends 
on the influence of light ; at any rate, it was soon lost in 
the dark. In the absence of a suitable food-plant 
the axis of the dodder (which is green in the seedling) 
does not assume the usual purple colour. ; 
PALZOLITHIC MAN IN NEW JERSEY! 
INCE Dr. C. C. Abbott’s discovery of Palzolithic 
implements in the river-deposits of Trenton, New 
Jersey, nearly forty years ago, the valley of the 
Delaware has continually attracted the attention of 
students of early man in North America. This region 
lies immediately south of the southern limit of the 
ice-sheet which extended over the greater part of the 
continent during the Glacial epoch, and it is covered 
by a thick stratum of boulder clay, with associated 
gravels, through which the existing rivers have cur 
their channels. The Trenton gravels occupy the 
valley excavated by the Delaware, and therefore re- 
present a period later than that of the maximum 
glaciation, though their constitution suggests that 
they date back to a time before glacial conditions had 
completely passed away. Over the Trenton gravels 
are spread yellow sands and loam, which Dr. J. B. 
Woodworth regards as Post-glacial; and there is also 
a thin superficial covering of black soil. All these 
three deposits yield evidence of man, and for more than 
twenty years they have been systematically searched 
and studied by Mr. Ernest Volk. His work has been 
done under the general direction of Prof. F. W. 
1 “* The Archxologv of the Delaware Valley.” By Ernest Volk. Papers 
of the Peabody Mus: um of Am-=rican Archzology and Ethnology, Harvard 
University, vol. vy. (Cambri’ge, Mass. rorr.) 
NO. 2221, VOL. 89] 
The alga, which enters a root | 
Putnam, for the Peabody Museum of Harvard Univer- 
sity, and an exhaustive, well-illustrated report of his 
results has now been published by the Museum. 
From Mr. Vollx’s researches, it appears that all the 
remains found in the surface soil and the pits and 
graves dug through it are those of the Indians who 
were displaced by the first European settlers. 
Numerous human skeletons were obtained, most of 
them buried in a crouching posture, with the knees 
drawn up towards the body, as well shown in several 
photographs. 
Traces of man in the underlying yellow sand and 
loam are rarer than in the black soil. Charcoal and 
pebbles broken by fire are found, but there is no 
pottery, and all the stone implements are of argillite. 
Some of the latter are obviously spear-heads, others 
are borers, and some are rudely made with a jagged 
cutting edge. Mr. Volk was fortunate enough to 
discover a few human skeletons undoubtedly of the 
same age, but the bones were too much decomposed 
for preservation, and merely showed that the people 
were strongly built. 
Discoveries in the Trenton gravel, with its inter- 
calated clays and sands, are still rarer. Mr. Volk 
notes chipped pieces of quartz and certain quartzite 
pebbles, which he regards as having been artificially 
broken. He also records fragments of a human 
cranium, and part of a human femur, which both he 
and Dr. A. Hrdlitka consider to have been cut and 
worked by man. In the same deposits were found 
identifiable bones of the musk-ox and the elk. 
Both Mr. Volk and the Peabody Museum are to be 
congratulated on the painstaking thoroughness of this 
interesting investigation, which it is to be hoped may 
be continued. In these days of overcrowded libraries, 
however, we must add a word of protest as to the 
undigested state in which the report is issued. It 
mav be of moment to the Peabody Museum to know 
that Mr. Volk did not work on Sundays or Washing- 
ton’s birthday, and was continually interrupted by 
rain, snow, ill-health, and ‘‘errands in town’; but 
these and innumerable other trivialities lengthen the 
text to an inordinate extent, while a large proportion 
of the 125 plates might well have been omitted with- 
out detracting from the value of the volume. 
ily “Soe 
RHEINBERG’S MICRO-SPECTRA METHOD 
OF COLOUR PHOTOGRAPHY. 
ae special features of the micro-spectra method 
of colour photography are, first, that by its 
means pictures absolutely faithful in colour, tone, and 
texture are obtainable by means purely optical with- 
out the intervention of any artificial colouring matter 
whatsoever, and, secondly, that it is a one-plate pro- 
cess involving nothing more than everyday black and 
white photography. A single negative is taken on a 
panchromatic plate, a lantern slide is made from it 
and placed in the position of the negative, white light 
is projected through the apparatus, and the picture, 
after slight adjustment, flashes out in its true colours. 
The theory of the process is a simple one. It 
consists in producing by optical means a surface com- 
posed of hundreds of complete but very narrow 
spectra, lying next to one another, the spectra being 
so close together as to render the individual colours 
indistinguishable to the unaided eye, so that the sur- 
face appears to be white. The photographic positive 
is used as a mask to block out or weaken those 
colours which are not. wanted, the remainder combin- 
ing to form the picture. 
The surface, composed of these contiguous narrow 
spectra, is produced by allowing white light to fall 
