228 
NATURE 
[ Fan. 4, 1883 
1. Accela. With digestive internal substance; without 
differentiation of a digestive tract and parenchym tissue. 
Without nervous system or excretory organs. All forms 
as yet known provided with an otolith. 
2. Rhabdoceela. Digestive tract and parenchym tissue 
differentiated ; a roomy body cavity usually present in 
which the regularly-shaped intestine is suspended by a 
small amount of parenchym tissue. With nervous system 
and excretory organ. Generative organs hermaphrodite 
(except in Microstoma and Stenostoma). Testes, as a 
rule, two compact glands. The female glands present as 
ovaries only, ovario-vitelligenous glands, or separate 
ovaries and yelk glands. Genital glands separated from 
the body parenchym by a special tunica propria. Pharynx 
always present, and very variously constructed. Otolith 
absent in most cases, 
3. Alloioccela. Digestive tract and parenchym tissue 
differentiated, but the body cavity much reduced by the 
abundant development of the latter. With nerve system 
and excretory organ. Generative organs hermaphrodite, 
with follicular testes and paired female glands, either 
ovaries only, or ovario-vitelligenous glands, or separate 
ovaries and yelk glands. Yelk glands irregularly lobular, 
rarely partially branched. Genital glands almost always 
without any tunica propria, lodged in the spaces in the 
body parenchym. Penis very uniform, and either without 
chilinous copulatory organs, or with these very little 
developed. Pharynx a pharynx variabilis or plicatus. 
Digestive tract lobular, or irregularly broadened out. All 
marine except one, or possibly two species. 
Under the Alloioccela come the genera—Plagiostoma, 
Vorticeros, Monotus, and others. 
The work commences with a complete list of the litera- 
ture on Turbellarians from the time of Trembley, who, in 
1744, figured a black fresh-water Planarian to that of the 
publication of the last of Dr. Arnold Lang’s important 
memoirs last year. The list is followed by a general treatise 
on the anatomy and physiology of the Rhabdoczelida. 
The account of the nematocysts of some forms is very 
interesting; their exact resemblance to those of Ccelen- 
terata is fully borne out. JZicrostonum lineare appears to 
be the only species which, like Hydra and Cordylophora, 
possesses two kinds of nematocysts. The author thinks 
he has been able to detect on the surface of the cuticle, 
trigger hairs in connection with the nematocysts, like those 
in Hydroids. He considers the rhabdites or rod-bodies 
homologous with nematocysts, and refers, in connection 
with this question, to the nematocysts devoid of any 
thread which occur inmany Ccelenterates, intermingled with 
fully developed ones. The structure of the pharynx is care- 
fully gone into, and its different forms being of much use 
in classification, receive various names, such as Pharynx 
bulbosus, P. plicatilis, &c. 
The water vascular system has been studied by von 
Graff with considerable success. It may consist of 
a single median main canal with a single posterior 
opening (Stenostoma) or a pair of laterally-placed canals 
with a similar single opening or two separate lateral 
canals with each a posterior opening (Derostoma), or 
there may be a pair of openings or a single one somewhat 
anteriorly placed. Ciliated funnel cells or flame cells 
such as exist in Cestodes, Trematodes, and Triclad 
Dendrocceles, have been discovered by von Graff also in 
the Rhabdoccelida. They do not, however, occur in con- 
nection with the tips of the ramifications of the water 
vascular canals, but almost entirely on the larger canals 
forming the networks. It is impossible here to follow 
the work further, through the interesting sections devoted 
to the development of Microstoma by budding, the habits 
of life and geographical distribution of the Rhabdoceelida. 
In connection with the discussion on classification, a table 
of the pedigree of Turbellaria is given, with Proporus as 
the ancestral starting-point. In this family tree the Den- 
drocceles are shown as derived from Acmostoma, a new 
genus of Alloioccela, characterised by having a distinctly 
marked narrow ambulacral sole, the Polyclada directly, 
and the Triclada through Plagiostoma. The ascertained 
facts as to the structure of Turbellarians seem to point 
even more closely to their connection with the Ccelen- 
terata. The presence of two kinds of nematocysts in one 
of the Rhabdoccela and possible occurrence in members 
of that group of trigger hairs, is a remarkable fact. Dr. 
Lang, believing that a part of the nervous system in 
Dendrocceles is truly mesenchymatous as in Ctenophora, 
and from other grounds concludes with Kowalewsky that 
the Polyclada are “creeping Ccelenterates which have 
manyspoints of structure in common with the Ctenophora, 
some with the Medusee. Such being the case, naturalists 
await with great impatience Kowalewsky’s promised 
further information as to his extraordinary Cceloplana, 
supposed intermediate between Ctenophora and Dendro- 
coelida. The peculiar azygos character of the otolith in 
so many Dendroccelida may perhaps be explained by the 
similar condition of the sense organ in Coeloplana. Prof. 
von Graff is much to be congratulated on the completion 
of this most important and admirable work. 
H. N. MOSELEY 
NOTES 
WE greatly regret to announce the death of Mr. Charles V. 
Walker, F.R.S., at his residence at Tunbridge Wells, on the 
morning of December 24, 1882, in the seventy-first year of his 
age. Mr, Walker had been Telegraph Engineer to the South- 
Eastern Railway, since 1845. He had been a most zealous 
worker in the science of electricity, as the many works he leaves 
behind will testify. Indeed, he was one of the oldest telegraph 
engineers in the country, was the inventor of several usefu 
appliances in connection with telegraphy, including the instru- 
ments by which the block system on railways is worked. His 
name is especially associated with the origin of the distribution of 
time by telegraph. On May 10, 1849, Mr. Glaisher wrote to 
Mr. Walker that he wished to talk with the latter about the 
laying down of a wire from the Observatory to the Lewisham 
Station, and on May 23 following, the Astronomer-Royal gave 
Mr. Walker a brief sketch of the use to be made of the wire 
referred to, his scheme, as he stated, being “ the transmission of 
time by galvanic signal to every part of the kingdom in which 
there is a galvanic telegraph from London.” It was proposed 
to lay four wires underground from the Royal Observatory to 
the railway station at Lewisham, and to extend them to London 
Bridge. The South-Eastern Railway Company gave every 
facility. On September 16, 1852, an electric clock at London 
Bridge Station was erected, and connected by wire with an 
electric clock at the Royal Observatory, Greenwich. The first 
time-signal sent from the Royal Observatory was received at 
London Bridge Station at 4 p.m. on August 5, 1852; and on 
August 9, 1852, Dover received a time-signal for the first time 
from the Royal Observatory direct, and it was made visible at 
certain first-class stations between London and Dover. After 
that the system rapidly spread, its success depending greatly on 
the scientific skill and enthusiasm of Mr. Walker. For some 
account of the subsequent development of the system, the reader 
may refer to the articles in NATURE, vol. xiv. pp. 50 and IIo. 
Mr. Walker was treasurer of the Royal Astronomical Club for 
several years, and at the time of his death was president of the 
Society of Telegraph Engineers. 
THE death is announced of Prof. Listing of Kénigsberg. 
THE honour of Companion of the order of the Indian Empire 
has been conferred upon Surgeon-Major George Bidie, Superin- 
tendent of the Central Museum at Madras. 
