Marcu 14, 1884.] 
which the water had been temporarily withdrawn, with 
a view to discover the winter condition of the fresh- 
water sponges and other inhabitants of that locality. 
Where the surface could be reached, it was found to be 
eovered with a mud-colored incrustation of consider- 
able thickness, which proved to be composed almost 
wholly of the statoblasts and spicules of the sponge 
Meyenia Leidyi. Some few fragments of Meyenia 
fluviatilis and Spongilla fragilis were seen, but the 
first named was clearly the prevailing species. A 
disused sluice-way was covered with a dry incrusta- 
tion of the same material. While considering the 
effect of the presence of so large a sponge-growth at 
the inlet to the supply-pumps, Mr. Potts stated that 
Meyenia Leidyi was conspicuous among the known 
North-American sponges by its great relative density, 
and the small proportion of its sarcode or flesh. Its 
decay, therefore, at the termination of its period of 
summer growth, would be a slighter cause of pollution 
to the water-supply than that of any other species. 
He was, moreover, inclined to believe that decay was 
not the normal or necessary result of the close of 
each season’s growth. The fragile branches of some 
- species inhabiting exposed situations may, of course, 
be broken off and destroyed while the sarcode still 
covers them; but in the sessile portions, and in all 
when sufficiently protected, the cells of the sarcode 
at the period of full maturity, forsaking their places 
along the line of the skeleton framework, gather 
together by simultaneous amoeboid movement into 
dense groups, where they are soon covered by a tough 
chitinous coat, which, in turn, generally becomes sur- 
rounded by a crust of minute granular cells, and 
armor-plated by a series of protective spicules. These 
groups are now recognized as the statoblasts, gem- 
mules, or winter eggs of the sponge. They are eggs 
only in appearance, being in reality the resting-spores 
or protected germs which conserve the life of the 
individual through the cold of winter. This life- 
history indicates rather a condensation than a decay 
of substance as winter approaches, and leaves little 
or no reason to regard such organisms as a source of 
water-pollution. 
Feb. 19. — Mr. Thomas Meehan exhibited twigs of 
the plant used by the Piutes and other western tribes 
of Indians for making baskets. They proved, on ex- 
amination, to belong to Apocynum cannabinum, the 
species used by the eastern Indians for a like pur- 
pose. —— Mr. Meehan called attention to sections 
of trees from Schuylkill county, Penn., illustrating 
remarkably slow growth. A black oak, Quercus tinc- 
toria, in a little over two inches from the centre, had 
an average’ of thirty-six circles to an inch; one of 
hemlock spruce, fifty-one circles to an inch; and one 
of the common chestnut, twenty-four circles to an 
inch. Though only four inches in diameter, the oak 
stem was seventy-six years old; the hemlock, four 
inches in diameter, was one hundred and four years 
old; and the chestnut had grown only four and a half 
inches in diameter in sixty years. He believed two 
hundred years to be the full average duration of most 
of the trees of the eastern United States. —— The 
same speaker, referring to the supposed parasitic 
SCIENCE. | 335 
nature of the snow-plant Sarcodes sanguinea, of the 
Rocky Mountains, stated that he had carefully ex- 
amined a specimen growing at an elevation in the 
Yosemite Valley, and found it to be existing independ- 
ently, no connection being traceable with either living 
or dead roots. No trace of vegetation was found in 
the soil which was carefully washed away, but a huge 
mass of coralline fleshy matter, out of which the in- 
florescence arose. The origin of this fleshy mass was 
yet an unsolved mystery. From analogy with the 
behavior of other plants, he was inclined to believe 
that there was some parasitic attachment in the early 
life of the plant, and that it stored up in this coralline 
mass enough nutrition in one season to support the 
inflorescence, after which the connection was severed. 
— Mr. Meehan also exhibited the dried leaves and 
fruit of Halesia diptera, H. tetraptera, and of a 
remarkable departure raised from the last-named 
species some years ago. This appeared in a bed of 
seedlings, all raised from seed gathered from one tree 
growing in a garden in Germantown. It attracted 
attention, when one year old, by the leaves bearing a 
resemblance to those of an apple-tree. The original 
tree had leaves narrowly lanceolate and acuminate, 
rather thin, pale green on the upper surface, and with 
no particularly prominent veins. The plant in ques- 
tion had broadly ovate leaves, scarcely pointed, very 
dark green, rugose on the upper surface, and strongly 
veined and hirsute below. The flowers, when they 
appeared, were open cup-shaped, instead of being 
drawn into a narrow tube at the base, as in the par- 
ent plant; and the pistil was wholly enclosed, and not 
exserted. For several years the plant was sterile; and 
many good botanists, whose attention was called to 
it, regarded the plant as a hybrid, and the sterility as 
a proof thereof. It was of no avail to point out that 
there was no other species from which the parent 
could have obtained pollen within many miles, nor 
to show that hybrids were not necessarily sterile. 
This season, however, the plant produced fruit. It is 
very small, not much over a quarter of an inch in 
diameter, and the four equal wings are comparatively 
large and of a strongly coriaceous character. The 
fruit which had been cut open was found to have 
perfect seeds. If the plant, with these leaves, flowers, 
and fruit, had been found in a state of nature, the 
botanists would surely have considered it the repre- 
sentative of a distinct species, if not of a new genus. 
While the suggestion of hybridity might be reason- 
ably excluded, change of surroundings could not be 
advanced as the cause of the variation, for the environ- 
ment was precisely the same for the sport, the seedlings 
which grew without change, and the parent stock. 
—— Professor Angelo Heilprin stated that among a 
small number of carboniferous fossils obtained from 
the border of Wise county. Tex., and submitted to 
him for examination by Mr. G. Howard Parker, a 
form occurs which can unhesitatingly be referred to 
the genus Ammonites. Only a fragment of a single 
individual is to be found; and this, unfortunately, has 
lost the shell, so that no external ornamentation, if 
any such existed, can now be discerned. This is the 
first Ammonites that has been detected in any Amer- 
