NOVEMBER 26, 1903] 
NATURE gt 
Tue Forms OF THE RING aND DumB-BELL NesBuLas.—In a 
recent number (539) of the Astronomical Journal Prof. J. M. 
Schaeberle stated that by using a short focus reflector he 
had obtained photographs of the Ring nebula which plainly 
showed that this object had a clockwise spiral form. In 
several fainter photographs obtained since, where faint 
nebulosities are shown only at the extremities of the major 
axis of the ellipse, he noticed a decided similitude in shape 
to the dumb-bell nebula in Vulpecula, and was induced to 
photograph the latter object in order to see if that, too, 
was a spiral; the photographs obtained show that it is, but 
in this case the spiral is counter-clockwise. 
From these photographs of the two objects Prof. 
Schaeberle concludes that they were formed, in each case, 
by simultaneous emissions of matter from a central mass, 
several streams leaving the parent body in diametrically 
opposite directions, and with various velocities, at the same 
time and forming inner and outer streams of which the 
inner would travel round the central body several times 
while the outer streams were making one revolution; where 
these two streams meet and are superimposed, the nebu- 
fosity is much brighter, and exhibits the forms usually 
attributed to these objects. If we suppose that the outer 
boundary of the nebula, as it is usually seen, represents 
the exterior limit of the inner streams, and that the general 
arrangement of the nebula is due to gravitational forces, 
this theory demands that the outer streams should extend 
much further than is generally shown on photographs, 
and, in proof of this, Prof. Schaeberle has obtained photo- 
graphs which show that various exterior nebulosities, and 
many of the adjacent faint stars, are probably part of one 
huge structure of which the Ring nebula is only the central 
condensation. 
Similar proofs have been obtained to show that the form- 
ation of the Dumb-bell nebula may be explained by the same 
hypothesis, for on several photographs it is plainly seen that 
various wisps of nebulosity, which are concave towards 
the Dumb-bell and include several streams of faint stars, 
are, with the Dumb-bell, probably parts of the same original 
mass (Astronomical Journal, No. 547). 
BIOLOGICAL WORK IN SOUTH AFRICA. 
“THE issue of the report of the Government biologist (Dr. 
J. D. F. Gilchrist) of the Cape of Good Hope for 1901 
affords a favourable opportunity for directing attention to 
the energy with which biological investigations are being 
carried on in South Africa. Several volumes of the excel- 
lent ‘“‘ Fauna of South Africa,’’ under the editorship and 
part authorship of Mr. W. L. Sclater, director of the Cape 
Town Museum, have from time to time been reviewed in 
our columns, where reference has likewise been made to 
various papers in Marine Investigations in South Africa, 
the Annals of the South African Museum, and other local 
publications. From some of these notes we venture to re- 
peat extracts on the present occasion. It may be added 
that, apart from local publications, Mr. O. Thomas, of the 
British Museum, in papers published in the Annals and 
Magazine of Natural History, has been able to increase our 
knowledge of the mammals of South Africa, thanks to 
collections sent to this country by Colonel Slogget, 
R.A.M.C. 
The Government biologist commences his report with an 
account of the trawling operations recently undertaken off 
the Natal coast at the request of the Government of that 
flourishing colony. The Natal coast is by no means 
promising for trawling, and as much money had been spent 
on previous occasions with no good results, and the recent 
trip proved equally unsatisfactory, the Government was 
advised to devote its attention to the development of line 
fishing, and to rely on the Cape trawling-grounds for its 
supply of soles. During the operations many new forms 
of marine life were procured, which are being investigated 
by specialists. On the return of the surveying vessel to 
Cape waters, a new trawling-ground was discovered, which 
promises to yield a valuable supply of food-fish. 
As regards inland-fisheries, breeding operations have been 
seriously hampered owing to the hindrances inseparable 
from the institution of martial law in the country, while 
an unfortunate case of poisoning did not tend to mend 
NO. 1778, VOL. 69] 
matters. Nevertheless, the director is able to report that 
the rainbow-trout are in a very satisfactory condition, and 
that carp are likewise flourishing. 
The report includes a reprint from Marine Investigations 
of Mr. R. Kirkpatrick’s first paper on the sponges obtained 
during the Natal and Cape cruises. The third part of this 
contribution (Marine Investigations, vol. ii. part iii.) is 
just to hand. Several genera and many species are de- 
scribed as new, and the author directs attention to a notable 
resemblance between the sponge-fauna of South Africa and 
that of Australia. 
A second paper reproduced in Dr. Gilchrist’s report is 
one by Mr. G. B. Sowerby on South African molluscs, in 
which is described a new species of Volutilithes, making 
the third existing representative of that genus, which was 
first described from the Barton Clay. Another contribution 
to this subject by the same author appears in vol. ii. of 
Marine Investigations, where a number of new forms of 
Pleurotoma and Conus, as well as representatives of other 
genera, are described. 
In the same volume the South African corals of the genus 
Flabellum receive attention at the hands of Mr. J. S. 
Gardiner who pays special attention to the anatomy and 
development of these organisms, and emphasises the im- 
portance of studying the polyp as well as the corallum if 
we hope to gain any real idea of their true relationships. 
This volume of Marine Investigations also contains some 
valuable notes by Dr. Gilchrist on the development of 
South African fishes. These notes have an important bear- 
ing on certain disputed points connected with the Cape 
fisheries. Many fishermen urge, for instance, that the 
spawn of several of the commoner food-fishes is developed 
on or near the sea-bottom, and is, in consequence, seriously 
damaged by trawling. To this the author replies that, 
since in northern waters it has been demonstrated that only 
one valuable food-fish, the herring, has deep-lying spawn, 
and since the Cape seas are the home of only a small species 
of herring of little or no commercial value, it is probable 
that the damage done by trawling in South African waters 
has been overestimated. 
Under the title of ‘‘ Rhynchotal Miscellanea,’’ Mr. W. L. 
Distant, in the Annals of the South African Museum (vol. 
ii. pt. ix. art. 12 and vol. iii. pt. ii. art. 3), publishes a 
series of notes on the bugs of the country, with descriptions 
of some new genera and a large number of new species. 
In vol. iii., part iii., of the same publication, Mr. G. A. 
Boulenger describes six new forms of perch-like fishes from 
the Natal coast, all of which are illustrated in well executed 
plates, and belong to previously known generic types. 
Part iv. art. 5 of the same volume is devoted to de- 
scriptions by Dr. W. F. Purcell of new spiders from South 
Africa belonging to five families. 
We must likewise refer to a communication in the Agri- 
cultural Journal of the Cape of Good Hope for October 
last, in which the Government entomologist, Mr. C. P. 
Lounsbury, records an important discovery in regard to the 
propagation of the South African sheep and goat disease 
known as “‘ heartwater.’”? The bont-tick has been found 
to be the only medium of spreading the disease. A single 
specimen, if fed on a heartwater-sick animal as a larva or 
“seed ’’ tick, is capable of transmitting the fatal malady. 
An animal pastured on veld infested by tick may drop 
thousands of larva during its illness, and thus serve for 
the extermination of a flock. The mortality amongst flocks 
brought to the coast where the tick is abundant is thus 
explained. Pathogenic larve retain their dangerous 
character until adult. They may take their second feeding 
on an Ox or a non-susceptible goat, and in the final stage 
get on to a susceptible sheep or goat and give it fever. 
On the other hand, the disease appears non-transmissible 
through the egg-stage, and the species is normally non- 
pathogenic in all stages. A farm may be infested with 
bont-tick, yet be free from heartwater. Since the other 
common species are innocuous, it is hoped that by keeping 
down the bont-tick the disease may be stamped out. 
By no means the least important memoir in the series 
before us is one by Mr. A. C. Seward oni the fossil floras 
of Cape Colony, forming part i. art. 1 of the fourth volume 
of the Annals. The first section deals with the flora of 
the Uitenhage series, which is regarded as of Wealden 
rather than of Jurassic age. The Stormberg, or upper 
