Zoology. 353 
scarcely injured at all, while those with a more deliquescent branch- 
ing suffered the loss of nearly all their branches. 
Elms usually bent their branches'until supported on the ground. 
Maples (Acer dasycarpum Ehrh.) acted very nearly as the Cotton- 
woods did, some breaking, while others withstood the strain. No 
hackberries (Celtis occidentalis L.) broke at all, their strong branches 
with axillary angles of nearly 90° rendering them strong enough 
to withstand the heaviest weight. 
White pines (Pinus strobus L.) suffered more than the Scotch and 
Austrian pines, the latter having (when young) more widely 
divergent branches than the former. Red Cedars and Balsam Firs 
trailed their lower branches upon the ground, while those above 
hung and rested upon those below. 
An attempt was made to estimate the weight borne by each tree, 
and the result showed that such ice burdens are very generally over- 
estimated. By melting the ice from a measured length of a twig, 
it was easy to estimate the amount of water carried by the tree. 
It was found that for a fine box elder, twenty-five feet in height, 
and with a large rounded top fully twenty-five feet in diameter, the 
total weight did not exceed three hundred pounds. The calcula- 
tion was carefully revised, because the result seemed too small, but 
lt was found to be correct. The effects which are so striking are 
clearly due to the fact that this weight, although so small, is borne 
as well by the slender twigs as by the larger branches. A weight 
of a few ounces upon the end of a lon twig produces a much 
oo bending than many pounds would at its base.— Charles 
essey. 
ZOOLOGY. 
SPONGES AND CŒLENTERATES OF AUSTRALIA.—Dr. R. von 
Lendenfeld has published a résumé of the facies of the Australian 
Species and varieties have been described from all parts of the 
‘oak and of these, no less than four hundred and fourteen have 
n I . . 
i 
cent. of the horn-s nges of any other region may be found in 
Australia ; and this is not limited by distance or any other barrier. 
