NoveMBER 8, 1906 | 
INCA IROGRIE. a1 
sent by far the stronger portion of the shower, will fall 
to the lot of American observers. 
The calculated intensity of the shower is rather inferior 
to that of its prototype of 1868; besides, the first maxima 
fall early in the night, and may not, therefore, be seen 
at their best. Nevertheless, the present epoch is a well- 
defined one, and should yield satisfactory returns to the 
vigilance of meteor observers. 
Of the minor showers associated with the period, the 
most interesting occur on November 16 between 13h. and 
14h., and on November 17 from 13h. to 18h. 
Dublin. Joun R. Henry. 
The Rusting of Iron. 
In reference to the discussion on the rusting of iron 
in recent numbers of Nature, I happen to have a curious 
specimen illustrating the accumulating of rust which may 
possibly be of some little scientific value. It is a horse- 
shoe which was dug up some years ago by a child out of 
the sand on the site of the battle of Prestonpans, near 
Edinburgh. It was given me by the child’s father, who 
was with him at the time. The shoe is now very irregular 
and lumpy. The thickness of the naked iron can be made 
out at one spot, where it is partially denuded. It is 
just three-eighths of an inch. But with the mass of what 
I can only describe as rust, and, I presume, sand—some 
small pebbles are, too, imbedded in it—it is in one spot 
as thick as 2 inches, and in girth it there measures 
62 inches. No part of it is wholly clear of rust; the 
smallest girth is 4 inches. 
The famous battle was fought on September 21, 1745, 
and the supposition is that the shoe, if not the horse, was 
lost there. The supposition is probable enough. If correct, 
the rust would represent the accumulation in a century and 
a half. I may add that I have some specimens of pig-iron 
which were turned out at foundries here fifty years ago, 
and have been in the open air ever since. They have just 
a brown coat, but the coat is of no perceptible thickness. 
JosEpH MEEHAN. 
Creevelea, Drumkeeran, October 29. 
PROTOZOA AND STATOZOA.* 
HE late publication of the first volume of this 
well-known series has enabled the authors to 
incorporate some of the results of the more recent 
researches upon their several subjects. Talsen in con- 
junction with the earlier published volumes, the work 
seems to fulfil the purpose of providing an intelligible 
and adequate survey of the entire animal kingdom 
without giving undue prominence to particular groups. 
Prof. Hartog’s share in the work makes a well- 
timed appearance in the year which has witnessed 
something like a crisis in the history of protozoology. 
His chapters are full of suggestive comparisons and 
analogies, and their value is increased by the addition 
of copious footnotes. Some of the statements are not 
supported by references, as, for example, where he 
speaks of the presence of a contractile vacuole in the 
zoospores of algz and fungi without mentioning any 
specific instances of this condition (p. 15). 
The essential complexity of the simplest manifest- 
ations of living matter is made evident, and Prof. 
Hartog does not harmonise the vitality of protoplasm 
with the vagaries of a drop of oil or of a bubble. 
The segmentation of the oosperm of Metazoa and 
Metaphyta is compared with the sporulation of the 
Protista, both phenomena being characterised as 
brood-formations (p. 31). 
In the second chapter the author begins with an 
1 “The Cambridge Natural History.” Vol. i. Protozoa. by Prof. Marcus 
Hartog ; Porifera (Sponges), bv Igerna B. L. Sollas ; Coelenterata and 
Ctenophora, by Prof. S J. Hickson, F.R.S.; Echinodermata, by Pro’. 
KE. W. MacBride, F.R.S. Pp. xvii+671; illustrated. (London: Macmillan 
and Co., Ltd., r9c6.) Price 17s. net. 
NO. 1932, VOL. 75 | 
interesting disquisition on the old belief in  spon- 
taneous generation as an explanation of the origin of 
the organisms of putrefaction, pointing out how this 
was due in part to the supposed inconstancy of species 
in Protista, and that this in turn resulted from the 
want of knowledge of their life-histories; how this 
knowledge was supplied in the first place by the Rev. 
W. H. Dallinger and Dr. Charles Drysdale for 
Protozoa, and for the Protophyta by F. Cohn and 
later by von Koch, who perfected the methods of 
culture devised by De Bary for the study of the fungi. 
In his remarks on reproduction by syngamy, Prof. 
Hartog distinguishes between exogamy and endo- 
gamy, the rhizopod Trichospherium affording an ex- 
ample of the exogamous conjugation of biflagellate 
isogametes, while the heliozoan Actinosphzerium 
practises endogamy. 
Referring to the pelagic foraminifer Globigerina 
(p. 61), the author says that after death the tests. 
sink to the bottom of the sea to form the ‘‘ Globerina 
ooze ”’ (sic), “‘ at depths where the carbonic acid under 
pressure is not adequate to dissolve the more solid 
calcareous matter.’”? On the following page we 
read :—‘‘ Some Foraminifera live on the sea bottom 
oe 
emo 
"4 (75> 
i 
Fic. 1.—Cerianthus membranaceus in its tube. Colour pink, with tentacles 
annulated pink and brown. About 35 cm. in length. From ‘The 
Cambridge Natural History,” vol. 1. 
even at the greatest depths, and of course their shell 
is not composed of calcareous matter.’’ There is 
nothing to indicate to the reader why this is more 
obvious than any of the other plain statements im 
the book. 
The last three chapters of Dr. Hartog’s treatise 
deal with the Sporozoa, the Flagellata, the Ciliata, 
and the Suctoria. As an illustration of the rapid 
strides of recent years, he notes that seven years ago: 
no single species of Sporozoa was known in its com- 
plete life-cycle. It would have been better to have 
used the general expression ‘‘ body-cavity ’’ instead 
of ‘‘ceelom’”’ on p. 105. Ccelom and hemoccel are 
both body-cavities, just as clothes props and thorough- 
breds are both horses ! 
The importance of investigations into the life- 
