JUNE 10, 1915] 
NATURE 
403 

with red crayon or sprayed with rosolic acid, and 
liberated to test their range of migration, which was 
found not to exceed 700 yards. 
A vivip account of the fauna and flora of the great 
forests and swamps of northern Queensland appears 
in the Victoria Naturalist for April by Mr. J. A. Ker- 
shaw, the Curator of the National Museum of Mel- 
bourne. In spite of rain and mosquitoes, much 
valuable field-work was accomplished. His account 
contains some interesting notes on crocodiles, fire- 
flies, and elephant beetles, and on the “bower” of 
the fawn-breasted bower-bird, a specimen of which 
was procured for the museum. 
An exhaustive and well-illustrated history of the 
midges (Chironomid) of Illinois, by Mr. J. R. 
Malloch, appears in the Bulletin of the Illinois State 
Laboratory of Natural History for May, which may 
be read with profit by those interested in the problem 
of the origin and evolution of species, as well as by 
students of the Diptera. The author describes the 
complete life-history of a most peculiar form of larva 
belonging to the Ceratopogoninz, which lives in sub- 
merged logs; and he has, besides, succeeded in dis- 
covering new characters which will materially lessen 
the labour of distinguishing the members of this 
sub-family, which is always a difficult task. 
INsTANCES of discontinuous distribution are always 
worth recording. Hence attention may well be 
directed to the surprising occurrence of a gnat 
(Culex hortensis) at Logie, Elgin, which, according 
to Mr. F. W. Edwards, in the Entomologist’s Maga- 
zine for May, was until recently not known outside 
the Mediterranean region. In 1913, however, it was 
recorded from the neighbourhood of Bonn. . The 
Scotch specimen differs from its congeners from 
southern Europe only in having the wing-scales 
slightly broader, and from the common British gnat 
(Culex pipiens) in having the white bands on the 
abdominal segments apical instead of basal, and in 
having broad, flat scales on the prothoracic lobes. 
THOSE interested in the behaviour of animals will 
find two suggestive papers in the Zoologist for May. 
In the first of these the Rev. H. Victor-Jones dis- 
cusses the vagaries of the parasitic protozoan Kerona. 
Contrary to the generally accepted opinion he finds 
that all three species of Hydra serve as its hosts, and, 
further, his experiments seem to show that when 
food is withheld from the Hydra the parasites migrate 
with impunity to the ccelomic cavity, ‘‘ wandering in 
and out with safety.”” Thus, he points out, Kerona 
can no longer be regarded as a strictly Ecto-parasite. 
Another interesting point raised in this paper is the 
nature of the stimulus which apparently controls the 
migrations of Kerona from the outside to the body- 
cavity. It would seem that the guiding factor in this 
migration is the search for food, from which the 
author infers that after all Kerona may have to be 
regarded as a commensal rather than as a parasite. 
In the second paper Mr. H. N. Milligan contributes 
some observations on the behaviour of a captive 
rockling (Motella mustela), which would seem to be 
one of the most timorous of fishes. The introduction 
NO. 2380, VOL. 95] 

of some common gobies into the tank, of which it 
originally was the sole occupant, caused a striking 
change in its habits, marked by an obvious mistrust 
of the new-comers. The author’s description of the 
association, which gradually manifested itself, between 
the movements of its fellow-captives and the advent 
of food, which always caused them to display the 
most extreme excitement, furnishes another example 
of the way in which instinctively nervous animals 
overcome groundless fear as a result of experience. 
A NEW edition of the Hand-list of Tender Mono- 
cotyledons—excluding orchids—cultivated in the Royal 
Botanic Gardens, Kew, has just been issued. For 
convenience of reference the plants are arranged in 
alphabetical order, which is a departure from the 
previous edition, but will no doubt be found more 
practical and serviceable, though perhaps somewhat 
less instructive at first sight. The present list con- 
tains many more names than were in the original 
edition of seventeen years ago, partly owing to acces- 
sions from Central and South America, South-east 
Asia, and especially tropical Africa, and partly also 
because the more important natural families of Mono- 
cotyledons have been the subject of careful study by 
botanists, which has resulted in the more exact deter- 
mination of the plants now under cultivation. The Kew 
hand-lists are of so much value to horticulturists that 
it is to be hoped it will soon be found possible to bring 
the other hand-lists up to date. 
Mow tronia, a new genus of Gesneracez, forms the 
subject of an interesting paper by Prof. Bayley Balfour 
and Mr. W. W. Smith in No. xl., vol. viii., of Notes 
from the Royal Botanic Garden, Edinburgh. As in 
some species of the genus Streptocarpus and in Mono- 
phyllea, only a single leafy organ is present, but the 
inflorescence is epiphyllous. The plant is considered 
to show a permanently embryonic vegetative state, 
the stalk and lamina being outgrowths from the 
primitive protocorm of the plant. The protocorm pos- 
sesses great meristematic activity, and gives rise in 
due course to the flowers. The plant is thus without 
stem, and probably without a true root. All that is 
developed is a cotyledon-like lamina from one end 
of the protocorm, which becomes the assimilating 
organ, and a long stalk which is hypocotylar in nature 
and probably gives rise to adventitious roots. An 
interesting comparison is drawn between this plant and 
the different types of Streptocarpus, and also with 
Chirita hamosa, where the flowers arise in a line on 
the upper surface of each petiole. 
SomE time ago the mathematical paradox referred 
to by “A. S. E.,”? in Nature of May.27, p. 345, was 
put in a much more striking form: ‘‘Suppose the 
earth spherical, and a cable laid along the equator in 
contact with the surface; its length would be about 
25,000 miles. If the cable were everywhere 6 ft. 
from the earth’s surface, how much longer would it 
be?” Led up to by talking about allowances for curva- 
ture in road-making, and by measuring circumferences 
of plates, etc., this is a good “catch” to try on your 
cleverest nephew at Christmas. Letters sent to NATURE 
on the subject give correct explanations of different 
