March 29, 1883 | 
Linnean Society, March 1.—Sir John Lubbock, Bart., 
president, in the chair.—The following gentlemen were elected 
Fellows of the Society :—W. B. Barrett, L. J. K. Brace, J. B. 
Bridgman, W. O. Chambers, W.E. Clarke, W. Godden, 
F. H. H. Guillemard, J. C. Havers, T. M. Hocken, C. H. 
Middleton Wake, James Stirling, and Rev. P. W. Wyatt.— 
Two pieces of North American yellow pine were exhibited for 
Mr. R. M. Middleton, which displayed on their surface a great 
number of depressions like fine shot holes. These were doubt- 
fully supposed to be produced by insect depredations. —Mr. 
W. T. Thiselton Dyer called attention to and made remarks on 
the dried leaves and rind of the fruit of oranges from the 
Bahamas, partially destroyed by the Mytilaspis citricola, 
Packard.—Mr,. R. F. Towndrow showed examples of a new 
variety of Rosa stytosa, obtained at Madresfield, near Malvern, 
by Mr. A. D. Melin. This variety is evergreen, and its fruits 
ripen in the second year.—Mr. Alfred W. Bennett read a paper 
on the constancy of insects in ther visits to flowers.—Then fol- 
lowed a communication on the methodic habits of insects when 
visiting flowers, by Mr. R. M. Christy, see notice (p. 498).— 
The Secretary, Mr. G J. Romanes, read some observations on 
living Echinodermata. He stated that star-fish possess a sense 
of smell which is not localised in any particular organs, such as 
the ocelli, but is distributed over the whole of the ventral sur- 
face. The function of the Pedicellariz was shown by some 
further experiments, corroborative of those already published by 
him in the Phzlosophical Transactions, to be that of seizing upon 
and arresting the movements of fronds of seaweed in order to 
give the pedicels time to establish their adhesions. It was also 
shown that the righting movements of echinus, when inverted 
on its aboral pole (which are performed by means of the 
pedicels) are due to central coordinatixn proceeding in part 
from the pentagonal nerve-ring surrounding the mouth, and in 
part from central nerve-matter distributed along the course of 
the radial nerve-trunks. One of the experiments whereby the 
fact of such central coordination (depending on a sense of gravity) 
was proved consisted in rotating an inverted echinus upon a 
wheel moving in a vertical plane. It was found that whatever 
phase in the righting manceuvre the echinus might have attained 
at the moment when the rotation commenced was maintained 
so long as the rotation continued, but the manceuvre was re- 
sumed so soon as the rotation was allowed to cease. The paper 
concluded with an account of the effects of the various nerve 
poisons on the Echinodermata,—There followed in abstract the 
17th part of the Rey. R. Boog Watson’s memoir on the mol- 
lusca of the Challenger expedition ; therein he deals with the 
family Pyramidellide, describing twenty-three new species of 
the genus Zudima, and one of the genus S¢y/ifer. 
Geologists’ Association, March 2.—Mr. W. F. Stanley 
read a paper upon the pos-ible causes of the elevation and 
subsidence of the earth’s surface. In this he offered an hypothesis 
that both the rising and sinking of land was entirely due directly 
or indirectly to the action of our great common motor, the sun. 
But most particularly for the greatest effects to the elevation of 
aqueous vapour, and to its after deposition as snow about the 
poles of the earth. The deposition of snow was assumed at the 
present time to reach a considerable altitude at the south pole, 
and in this position by its gravity to react as a pressure upon 
the interior mass of the earth, which was assumed to be in a 
highly heated viscous or semi-liquid state, and to be surrounded 
by a somewhat rigid crust of 200 miles or so in thickness. The 
crust was assumed to offer a certain amount of resistance to 
internal and external pressures, beyond which it was deflectable 
upon or from the viscous interior. The pressures from continued 
accumulation of snow at the poles acting as an hydraulic pressure 
upon the interior mass were assumed to be distributed in such a 
manner as was evident by elevation of land in volcanic and 
plutonic action, so that the earth could remain approximately 
under the conditions present, a symmetrical spheroid whose 
outward figure would constantly represent a natural resultant of 
the action of gravitation upon all its parts, and of the tangential 
force of such parts in revolution. It was argued that the 
stability of the land-surface was entirely due to sermanent 
elevation by volcanic and plutonic action, and that if this did not 
exist the effects of atmospheric denudation would reduce the 
land surface within moderate geological time to a nearly level 
swampy plane. It was further discussed that if the interior of 
the earth is metallic, which has been reasonably inferred from 
its high specific gravity (about 5°6), then it would consist of a 
heat-conducting material, so that, beyond the non-conducting 
NATURE 
523 
coating, which we term the crust, a certain degree of heat would 
be reached which might henceforth remain uniform throughout 
the interior mass. The crust would therefore be that portion of 
the exterior which was oxidised into a non-conducting coating in 
which the interior heated mass would conserve its heat with 
little loss. It was further argued that if the interior were a 
viscous mass the reaction of hydraulic pressure upon it, as from 
great accumulation of ice at either pole, would be made most 
evident about the most deflectable parts of the crust, so that the 
central mass might remain static, and if this was assumed by the 
presence of enormous pressure to form a practically incompres- 
sible semi-liquid, it would in this state possess enormous rigidity. 
Mr. Stanley further discussed the conditions of continuity of 
voleanic action throughout all time that the earth bas existed as 
a cooling globe with a solid crust accumulating ice at either of 
its poles, and that the periods of greatest glaciation at either pole 
would be the periods of greatest volcanic eruption and elevation. 
Dr. Croli’s theory of displacement of the earth’s centre by polar 
glaciation was shown not entirely to coincide with observation, in 
that the coast of Greenland was sinking, and the coast of 
Nerway, in the same latitude, was rising whereas by this theory 
of displacement of the earth’s centre, the present accumulation 
of ice at the south pole should cause both of these parts to be 
rising equally. Mr. Stanley held that the cause of the coast of 
Greenland sinking was the weight of the present accumulation 
of ice upon that continent, which represented on a small scale a 
polar pressure system such as he had discussed. 
Royal Horticultural Society, March 13.—Sir J. 1}. 
Hooker, K.C.S.I., in the chair.—Potato-disease ; Dr. Masters 
read a portion of a paper on this subject forwarded to him by 
Mr. A. Stephen Wilson, and having especial reference to the 
“*sclerotia ” which Mr, Wilson has discovered in nearly all the 
organs of the adult plant, as well as in the seedlings and tubers. 
The sclerotia are supposed to germinate and lie in a state of 
incubation in the haulm. Ultimately they give rise to the 
conidial threads. The conidia form, according to circumstances, 
either (1) zoospores, (2) plasm granules, or (3) secondary conidia. 
These are succeeded by oospores and a non-parasitie mycelium, 
from which latter, as it creeps through the soil, are thrown out 
“floats” and specks of the seminal plasm. The seed-tuber 
comes into contact with the plasm in the soil, which is absorbed ard 
becomes developed in the shape of sclerotia, and thus the life- 
cycle is completed. From the tuber or seed to the conidia is the 
parasitic arc. From the conidia to the tuber is the non-parasitic 
arc. The author illustrated his position by what happens in the 
case of cereals, wherein the plasm, say, of smut or rust, is ab- 
sorbed by the cells of the scutellum or cotyledon, passes through 
a period of gestation and then germinates. Mr. G. Murray 
observed that a microscopical examination did not clearly reveal 
any organic connection between the sclerotia and the perono- 
spora mycelium, and thought that possibly they might prove tu 
be glandular bodies of some kind, and belonging to the potato 
itself. Moreover they could not be true sclerotia in the fungoid 
sense, as the latter are a compact mycelium.—Retinospora pistfiva 
and FR. plumosa: Mr. Noble sent a specimen exhibiting sprays 
of both of these supposed species on the same plant. Dr. Mas- 
ters remarked that the latter is the young form, while the former is 
the adult, and that a microscopical examination showed a corre- 
spondingly different distribution of the stomata, being more 
numerous in . plumosa.—Funiperus Chinensis: He also sent 
a male spray taken from a female plant; the sexes in this 
species being normally quite distinct.— Garrya elliptica grafted on 
Aucuba Faponica : Mr. Noble forwarded a specimen showing 
the stock and the graft united. Mr. Henslow observed that this 
was an instance where physiological affinity corroborated the 
morphological; in that while Endlicher had placed Garrya 
between the hop and the plane, Bentham and Hooker assigned 
its position in the ‘‘ Gen, Plantarum” next to Aucuba ; but the 
discovery of its power of grafting on Aucuba was purely acci- 
dental, having been made by a gardener in Mr, Veitch’s nurseries. 
—Carica, hybrid: Mr. Green, gardener to Sir G. Macleay, sent 
ripe fruits and foliage of a plant grown from seed furnished by 
M, Van Volxem of Brussels, It is a hybrid of the second 
generation, the first being raised from C. erythrocarpa, im- 
pregnated with the pollen of C. cundinamarcensis (from 
Colombia). From the fruit of this cross seedlings were raised, 
which were impregnated with pollen from the last named species, 
or from the hybrid itself. Some of the fruits supplied by Mr. 
Green contained apparently good seed. Mr. Henslow has tried 
the effect of the foliage on meat, that of the ‘‘ Papaw,” 
