Scientific Intelligence. 97 
species as those that co-existed with the mammoth, tichorrine, 
rhinoceros, cave hyzna, bear, &c., so likewise the remains o 
small sloths and armadillos are found associated with the Mega- 
therium and Glyptodon in South America ; the fossil remains of 
ordinary kangaroos and wombats occur together, with those of 
gigantic herbivorous Marsupials; and there is similar evidence 
that the Apteryx existed with the Dinornis ; and the author offered 
the following suggestions as more applicable to, or explanatory of, 
the phenomena than the theory of transmntation and degrada- 
tion. He observed that in proportion to the bulk of an animal 
is the difficulty of the contest which, as a living being, it has to 
maintain against the surrounding influences which are ever tend- 
ing to dissolve the vital bond, and subjugate the organized mat- 
ter to the ordinary chemical and physical forces. Any changes, 
therefore, in the external circumstances in which a species may 
have been created to exist, will militate against that existence, in 
probably a geometrical ratio to the bulk of such species. If a 
dry season be gradually prolonged, the large mammal will suffer 
from the drought sooner than the small one; if such alteration of 
climate affect quantity of vegetable food, the bulky Herbivore will 
first feel the effects of the stinted nourishment; if new enemies 
are introduced, the large and conspicnous quadruped or bird will 
fall a prey, whilst the smaller species might conceal themselves 
and escape. Smaller quadrupeds, are usually also, more prolific 
than larger ones. The actual presence, therefore, of small spe- 
cles of animals in countries where the larger species of the same 
hatural families formerly existed, is not to be ascribed to any grad- 
ual diminution of the size of such larger animals, but is the re- 
sult of circumstances which may be illustrated by the fable of the 
‘oak and the reed,”—the small animals have bent and accommo- 
dated themselves to changes under which the larger species have 
succumbed. 
ee 
SCIENTIFIC INTELLIGENCE. 
I. CuemistRy AND Puaysics. 
- Transmission of Radiant Heat through Crystals. —KNoBLavcn 
1 
has studied the transmission of heat through erystals in different direc- 
he rac beat em- 
lows. 
gh certain crystals, as smoky 
quartz, beryl, tourmalin, and dichroite, in unequal proportions in different 
directions, and afier transmission exhibits different properties (with re- 
Stoonp Szrtes, Vol. XIV, No. 40.—July, 1852. 18 
ss, 
ig 
