Weekly national intelligencer. [volume] (Washington [D.C.]) 1841-1869, 1851-02-22
SMITHSONIAN LECTURES.

SMITHSONIAN LECTURES.
Dr. GoADBr continued his interesting course of lectures
Friday evening last and entered upon the investigation Of
nutrition in the animal kingdom generally, and made espe
cia reference the notifications Of the digestive apparatus
as it exists in the class mammals.
He illustrated the form of the human subject by lanspa-
rent diagram and described its structure and function. The
four somachs of the rumnant quadruped were in like
represented and the process Of digestion explained The
peculiar apparatus necessary for the uraon Of grain
animal unPovided with teeth next described and illus
uaed by reference to the gzzard of the domestic poultry.
Inc Dat 10 capable Of feeding indiscrmnaey upon either
nesn or gram combining in this respect the capabilities Of
TWO very distinct animals viz the canivoreus and graminv
ofous varieties The creature has bat one stomach differing
IN orm rom that of other mammala and arranged that
contains the Peeuiaries Of two very distinct organs The
@soYnagus placed nearly in the centre Of the largest diam
eer Oh ns curious digestive cavity and line Of demarcson
Is seen little side of the entrance of the ssophagus
separstng two very different structures On one side of the
line there is highly vascular membrane secre,ing
gastric juice and capable of reducing animal food in the same
the stomach Of man, and the carnvoous tribes act
the like MATERIAL while the other side of the line is
found hard calous nonvaseuar membrane analogous in
form and function to the lining embane of the gizzad of
fowls and in this part of the stomach grain is .ruraed
This was illustrated also, by transparent diagram.
In the higher crustscea, the lobster crabs &c. there IL
mouth, provided with pair Of strong jaws for cutting the
food and numerous instruments hands for holding
or prehension and afterwards conveying the food into the
mouth The stomach is very capacous one composed Of
membrane remarkable for M toughness, and supported by
number of bones Of considerable density the whole covered
externally by powerful muscles On sitting it open the
interior is found studded with minute teeth and in
the valve of exit Of tho nument The pyloc valve is
composed Of three teeth Of very large size, and of great
strength. Two of these form pair of powerful molar or
grinding teeth, while the third fiat base, rounded
its apex, and forms atabe which the food while the
grinders act upon it and assist in supplying these teeth by
constantly introducing unmascased particles between the
grinders The whole arrangement is popularity known as
"the lady in the head Of the lobster"
Amongst the accessory organs belonging to the nutriive
Junction. the salivary glands and liver prominent
and important The liver is almost universally found in the
animal kingdom, existing in low in the scale of
being, and il makes its appearance long before find any
trace Of salivary glands.
Glands of all kinds in the class Of insects exist in their
simplest elementary form, although there few ex-
cepons this rule and chiefly conne1ion with the sail
glands The saliva in all animals capable Of secreng
it is of great importance in preparing food for the action Of
the gastric juice secreted by the stomach II possesses in
all animals peculiar chemical properties it destroys any
vitality remaining in the food scads IL and oosens all it's
tissues that the gastric fluid readily permeate it, and
speedily reduce the into soft pulp. Moreover,
dutes the food 1t is for the purpose Of thoroughly insa
waiting the food that the hebvorous animals chew the
for by the sowe careful process Of mascaton to which the
crude at this time particle of the
living vegetable brought into contact again and again with
saliva BY of which the changes already alluded
effected To the chemical properties of the saliva
hydrophoba from the bite Of dog, in cat
neither Of them being rabd the time Of incng the in
jury To the same property may be ascbed the fatal effects
resulting from the bite of ratesnake for the dreaded poison
which they convey into the wound though the tubular canals
Of the poison angs, is nothing than the savsy
ton and the angs but the continuation of salvay Ducts
Numerous other ansloges given by the lecturer in
connection with the curious phenomenon, solely reeabe
the savary secretion of the higher animals and Of insects
and be concluded with the demonstration and exhibition Of
the savary glands Of vegetable eedng caterpar-the
Cossus Lgniperda The remainder Of the subject
ferred to the lecture of this evening