608 
NATURE 
| APRIL 29, 1897 
understand by “the group of worms”? What are the 
characters of “that great extinct group”? while there 
may even be many who will ask, What does Mr. Gamble 
mean by the Annelids? All these questions will be 
asked in vain, so far as the “ Cambridge Natural History ” 
is concerned, if we except one small allusion to the “ old 
term Annelida,” which occurs in Mr. Benham’s con- 
tribution ; and it is answers to these questions, and to 
others like them, that we think should undoubtedly have 
been furnished by the editors. A similar complaint has 
been made in more than one place concerning the 
previous volumes of this series, and we venture to think 
that the complaint is especially justified in the present 
instance, if we are to regard this work in the light of 
anything else than a cyclopedia intended for the con- 
venience of the fairly advanced zoologist. 
When so many writers combine in a volume of this 
kind, it would be too much to expect that each of them 
should write on precisely the same lines or in a similar 
style ; indeed, if we remember rightly, the prospectus of 
the “Cambridge Natural History” stated that con- 
siderable freedom would be allowed to individual authors. 
None the less, some attempt should have been made to 
settle how far this work is intended to be a popular one, 
since this is undoubtedly a question which the various 
authors have answered in exceedingly different ways. 
So far as we ourselves understand the aim of the series, 
nothing could be better or more appropriate than the 
chapters on Polyzoa, contributed to this volume by one 
of the editors, Mr. Harmer. Beginning with an allusion 
to common forms that may be found on the sea-shore, 
describing the beauty that a very slight examination 
will disclose in an unattractive-looking “dry piece of a 
brown paper-like substance,” FVustra foliacea, he leads 
his reader on by gentle degrees to understand the mean- 
ings of the words “zooecia,” ‘“avicularia,” and the like, 
and then explains to him the general characters of the 
Polyzoa. This done, the reader can appreciate with 
rather more interest the short account of the history of 
our knowledge of the group, and is prepared to learn in 
further detail the characters upon which the classifica- 
tion is based. The account of the various groups is 
interspersed and enlivened by remarks on their habits 
and life-history, containing many observations which 
appear to us to be original. The section ends with not 
the least valuable portion, a guide to the genera and to 
many species of British marine Polyzoa, with an account 
of how to make the necessary preparations. Whatever 
opinions we may hold with regard to the different points 
in Mr. Harmer’s chapters, it does not seem to us that a 
better method for interesting and instructing, as well as 
for encouraging further research, could be devised. 
It were to be wished that Mr. Harmer had opened the 
whole series with this section of his, or that he had had 
it printed and sent round to the various contributors for 
their guidance ; for it cannot be said that his collabora- 
tors, at least in this volume, have been equally happy in 
their mode of attacking what we admit to be a very 
difficult problem. It does not, for instance, strike us 
that the average reader is likely to feel himself further 
drawn to the study of natural history in general or to 
that of the Chietopoda in particular, by the opening 
sentences of Mr. Benham’s narrative, nor will the reader 
who has yet to learn what a gephyrean is, be particularly 
interested by such a paragraph as this :— 
“The animals included in the above-named group 
were formerly associated with the Echinodermata. Delle 
Chiaje states that Bohadsch of Prague in 1757 was the 
first to give an accurate description of Szpuculus under 
the name of Sy-izx, but Linnzeus, who noted that in 
captivity the animal always kept its anus directed 
upwards, re-named it Szpunculus. Lamarck placed the 
Gephyrea near the Holothurians; and Cuvier also 
assigned them a position amongst the Echinoderms. 
NO. 1435, VOL. 55] 
He mentions Bonellia, Thalassema, Echiurus, Sternaspis,. 
and three species of Szfunculus, one of which, S. ediu/is, 
““sert de nourriture aux Chinois qui habitent Java, et qui 
vont la chercher dans la sable au moyen de petits 
bambous préparés”—a paragraph that forms Mr. 
Shipley’s introduction to the group. 
Adequately to discuss and to criticise these numerous 
contributions would lead us into details more fitted for a 
technical zoological journal ; but there are one or two 
thoughts that have occurred to us in reading the book, 
and these may perhaps be mentioned. 
Is it not rather misleading to retain a name of such 
definite meaning as the name Mesozoa for the strange 
animals that compose the families Dicyemidz and 
Orthonectidze, and moreover to print this name Mesozoa 
in the scheme of classification with similar type and in 
similar position to the names of the recognised phyla, 
when, as Mr. Gamble himself tells us, they “are most 
conveniently (and probably rightly) considered as an 
appendix to the-Platyhelminthes” ? If the name be kept 
at all, it should at least be explained to the inquiring 
mind what those features are which made Van Beneden, 
the discoverer of the group, consider these animals as 
intermediate between the Protozoa and the Metazoa. 
A somewhat similar point is the hesitation as to the 
position of the Nemertines; they are treated in a 
separate section by a separate author, Miss L. Sheldon, 
and yet it is pretty clear that she inclines to the view 
that they should be placed among the Platyhelminthes 
—that is to say, if Birger’s recent discovery of flame- 
cells be not disproved We do not mean to say that we 
wish Mr. Gamble and Miss Sheldon to exercise anything 
but a scientific caution. Nevertheless, these are excel- 
lent instances of the questions that might so well have 
been discussed in a separate chapter by the editors. 
There is naught of popular interest to be said 
about the Nemertines, so that Miss Sheldon’s chapter, 
perhaps inevitably, reads much like an excerpt from 
the ordinary text-book of zoology. Mr. Gamble’s 
lot is cast in happier plaves ; he has to deal with the 
tape-worms, the liver-flukes, the formidable Bz/harzia— 
the cause of hzematuria, and other creatures of as muck 
economic as zoological interest. With reference to the 
liver-fluke of the sheep, Mr. Gamble speaks as though its 
intermediate host were only the water-snail, Lzmnea 
truncatula, or varieties of that species. The Rev. W. 
Fielder and others, however, in Victoria, have recently 
discovered large numbers of the peculiar stages known 
as vedia and cercaria in species of other fresh-water 
molluscs belonging to the genera /s¢dova, Segmentina, 
and P/anorbis; and since these larval stages are similar 
in form to those found in Lzmnca truncatula, there is 
reason to suppose that we have to do with the ordinary 
sheep liver-fluke. In any case, a large number of inter- 
mediate hosts, not mentioned in Mr. Gamble’s table on 
pp. 71! and 72, have been noticed by the energetic 
Victorian naturalists. 
A similar addition might have been made on p. 143, 
where Strongylus, a genus of nematodes or thread- 
worms, is mentioned as being found in horses, cattle, and 
sheep, birds, and reptiles, but not as having been found — 
in man. Looss not long ago described a_ species, 
Strongylus subtilis, found in the intestines of Egyptian 
fellaheen, while more lately still Prof. Ijima, of Tokyo, 
has stated that a species, which appears to be the same, 
has long been known in Japan as a human endoparasite- 
A plague that in March 1889 spread among the inhabi- 
tants of the Miura peninsula appears to have been due 
to the growth of this species. Mr. Shipley mentions 
that no intermediate host has been satisfactorily demon- 
strated ; it may, therefore, be of interest to mention that 
Dr. Ogata, who investigated the Miura plague, and first 
discovered the existence of S¢rongy/us in the stomach of 
one of its victims, believed, after much investigation, 
