FEBRUARY 8, 1884.] 
tember. Two species of morel, Morchella esculenta 
and Gyromitra esculenta, are also common, and are 
very desirable food-supplies; while the Lycoperdons, 
or puff-balls, are found in immense numbers, and 
often of large dimensions, and, when young, are ex- 
cellent for the table. Among poisonous forms, the 
fiy-agaric, Amanita muscaria, was instanced as one 
of the most highly organized, most widely distrib- 
uted, most beautiful, and most dangerous of the 
agarics. The difficulty of distinguishing by sight 
between many edible and non-edible or poisonous 
species was stated; and it was explained that those 
having a pleasant odor and taste were always likely 
to be eatable and harmless, while others would be 
more or less injurious. It is, however, always 
advisable, at first, to eat but a small quantity of 
any untried species. Professor Macoun, as botan- 
ist to the Geological survey, is now working at the 
fungi of Canada, and is preparing a report thereon 
for publication. Beautiful plates to illustrate this 
report have been drawn by Mrs. Chamberlin, a 
member of the club; and such as related to the 
forms discussed were exhibited by her, to the. great 
gratification of the members. — The secretary laid on 
the table advance copies of the Transactions of the 
elub for 1882-83, and announced that they would 
be ready for distribution in a few days. 
Princeton science club. 
Jan. 25.— Professor Rockwood gave a paper on 
the mutual relations of the conics, discussing espe- 
cially the changes by which the different curves turn 
one into another through their limiting forms. He 
traced the various curves represented by the equation 
A2y? + Bz? = A? B?, when A? is constant, and B? 
assumes all possible values, showing them to include 
all the varieties of the ellipse and hyperbola. In 
2 .B* 1553 
the same way the equation 7? = eee re x? was 
shown to include all forms of the conic when A and 
£& assume various values, — zero, infinite, or finite. 
in tracing the movement of the foci, he showed that 
in the series of ellipses and hyperbolas the foci come 
first to coincide at the centre; afterward their dis- 
tance from the centre becomes c V — i winielt,, Dy: 
interpreting the imaginary factor as indicating revo- 
lution through a right angle, changes the foci from 
the horizontal to the vertical axis, on which they then 
recede to infinity, returning from infinity on the hori- 
zontal axis when the ellipses change through two 
parallels to the series of hyperbolas. The changes 
were also followed out with focus and directrix fixed 
and eccentricity varying, with focus and focal ordi- 
nate fixed and eccentricity varying, etc. 
Professor Scott reported that he had just discov- 
ered a rudimentary pollex in Oreodon of the White 
River miocene. The carpus is very primitive in ar- 
rangement, and a trapezium is present. 
New-York academy of sciences, 
Jan. 21. — Two specimens of corundum from west- 
erm North Carolina were exhibited by G, F. Kunz. 
One was a crystal weighing 13 grams: the other, 
7 
SCIENCE. 
165 
weighing 3+? carats, was cut en cabachon, and by the 
exhibiter was said to be the most perfect star-sapphire 
probably yet found in the United States. Both pieces 
were a rich light-brown color, very compact, and re- 
sembled a variety of sapphire from the hills of pre- 
cious stones in Siam. Prof. H. L. Fairchild delivered 
a lecture on methods of animal self-defence, which 
was well illustrated with a large series of well-selected 
lantern-slides. Remarks were made by President 
Newberry and Prof. W. P. Trowbridge. 
Canadian institute, Toronto. 
Jan. 19. — Prof. R. Ramsay Wright gave an account 
of researches on the skin and nervous system of 
Amiurus catus, which will shortly be published in 
the Proceedings. Special attention was devoted to 
the ‘clavate’ cells of the epidermis, to the branch- 
ing of the fifth nerve, and to the relationship between 
the air-bladder and auditory organ. 
Natural science association of Staten Island, New Brighton, 
Jan. 12.— Mr. C. W. Leng read a paper on the 
Cicindelidae of Staten Island. The beetles live all 
summer in sunny places in the woods, roadsides, 
and on the sands at the seashore. They are able to 
make short flights, which they do at the least alarm, 
flying a few paces at a foot or two from the ground, 
and then dropping quite suddenly. Their colors 
always mimic the places at which they are found, 
which makes it difficult to distinguish them after 
they alight. During the night and rainy days they 
hide in holes dug in the sand, or among piles of chips 
and bark. The following eight species have been 
found on Staten Island: C. sexguttata, purpurea, 
generosa, tranquebarica, repanda, hirticollis, dorsalis, 
punctulata. 
Remarks were made by Mr. Sechusen on a very 
interesting series of precious stones, their particular 
characters, and the localities from which they came. 
Society of arts, Massachusetts institute of technology. 
Jan. 10.— Dr. Charles S. Minot, of the Harvard 
medical school, read a paper giving an account of his 
researches on growth and death. Dr. Minot has 
undertaken an extensive series of experiments, which 
will occupy many years, on senescence, or the process 
of growing old; and he presented in this paper the 
results of one branch of his investigations, in which 
he had studied the growth of the guinea-pig from 
birth until the attainment of the full size, having 
made about fifty-five hundred weighings of these ani- 
mals, the weight being the function of growth best 
adapted for study. 
In 151 recorded births, the proportion of males to 
females was found to be 119 to 100. The average 
weight at birth was about 72.5 grams, and was about 
the same for males and females. The range was from 
42 to 99 for the males, and 46 to 111 for the females. 
The most potent influence on the weight at birth was 
found to be the number in a litter; the larger the 
litter, the less the average weight. The period of 
gestation was found to average 67 days; and the 
longer the period, the greater the weight at birth 
