634 
geny of the aphis. By reprodufion or- 
ganic beings are gradually enlarged and 
improved ; ** thus (fays he) the buds of 
& feedling tree, or the bulbs of feedling 
tulips, become larger and ftronger in the 
fecond year than the firft, and eee 
prove till they acquire fawers or, Mexes : 
“and the aphis, I believe, increafés in bulk 
to theeighth or ninth generation, and then 
produces a fexual progeny. ‘Henee the 
exiftence of {pentaneous vitality is only to 
be expected to be found in the fimpleft 
moles of animation, as the complex ones 
have been formed by many fucceffive re- 
productions.” 
From. thefe pclrainaty obfervations, 
Dr. Darwin proceeds to exper imental fats : 
«< By the experiments of Buffon, STO 
Ellis, Ingenhouz, and others, microfcopic 
animals are produced in tbree orfourdays, 
according to the warmth of the feafon, in 
the infufions of all vegetable cr animal 
matter. One or more of thefe gentlemen 
put fome boiling veal-broth iro a ‘phial, 
previoufly heated in the fire, and fealing 
it up hermetically, or with melted wax, 
oblerved it to be replete with animalcules 
in three or fourdays.” ~** To fuppofe the 
eggs of thefe animals to float in the atmo- 
fphere, and pafs through the fealed glafs 
phial, is fo contrary to apparent nature, as 
to be totally incredible.” Again: ‘* In 
pafte compofed of Hour and water, which 
has been {fuffered to become acefcent, the 
animalcules called eels, vibrzo anguillula 
are feeh in great abundance ; their mo- 
tions are rapid and ftrong ; they are vivi- 
parous, and produce at interva als a nume- 
yous progeny : animals fimilar to thefe are 
allo found in vinegar; Natuxali/?s Mifcel- 
lany, by Shaw and Nodder, vol. i].— 
As theie animals are viviparous, it is ab- 
jurd to fuppofe that their parents float uni- 
verfally in the atmofphere to lay their 
young in pafte and vinegar ! 
The conferwa fontinalis of Dr. Priet-- 
ley is a vegetable body which appears to, 
be produced by a fpontaneous vital pro- 
cefs. Dr. Ingenhouz aflerts, ** that by 
filling a bottle with well-water, and in-’ 
verting it immediately into abafin of well- 
water, this green vegetabie is- formed in 
great quantity ; and he believes, that the 
water itfelf, or -fome fubftance contained © 
in thewater, is converted into this kind of 
vegetat.on, which then quickly propa- 
gatesitfelf.” 
Mucor, or mouldinefs, 1s another vege- 
table, the incipient growth of whicn Mr. 
Ejlis obferved by his microfcope near the 
furface of all putrifying vegetables or 
animal matter. 
Retrofpeet of Dameftic Literatnre.— Poetry: 
After having proceeded thus far, Dr. 
Darwin unfolds his theory of fpontaneous 
vitality ; it will be recognized. as extreme- 
ly fimilar to the theory of glandular fecre- 
tions, laid down in Zoonomia, and after- 
wards applied to vegetable reproductions, 
in Phytologia. As in animal or chemical 
combinations, one of the! compefing: ma~ 
terialsmuft poflels a power of attraction,, 
as the magnet, and the other an aptitude 
to be attracted, as a piece of iron: fo in 
vegetable or animal’ ednibitaHons there, 
mut exit two kinds of organic. matter, 
one poffefiing the appetency to unite, and 
the ether the propenfity to be united.—, 
Thus in the generation of the buds of 
trees, it is probable that two kinds of ve- 
getable matter—one of them endued with 
this appetency to unite with the other,’ 
and the latter with this propenfity to be- 
united with the former—‘* as they are fe- 
parated from the folid fyftem, and float’ 
in the circulation, become arrefted by 
two kinds of vegetable glands, and are’ 
then eres beneatn the cuticle of the 
tree, and there join together, forming a 
new vegetable, the caudex of which eX>_ 
tends from the plumula at the fummit to 
the radicles beneath the-foil, and contti- 
tutes a fingle fibre of the bark ; fo in 
the fexual reproduction of nérbweales cer= 
tain parts, feparated from the living or- 
gans, and floating in the blood, are ar=" 
refted by the fexual glands of the female, 
and others by thofe'of the male. Of thefe. 
none are complete embryon animals, but, 
form an embryon by their reciprocal con- 
junction. 
tion, as one is the production of new or- 
ganization, and the other the reftoration 
of that which previoufly exifted, and. 
which therfore may be fuppofed to re- 
guire materials fomewhat fimilar, Now. 
the food taken up by animal lacteals is 
previoufly prepared by the chemical pro-_ 
cefs of digeftionin the ftomach 5 but that, 
which is faken up by vegetable fatteals i is 
prepared by Chewieal diffolution of or-_ 
ganic matter formed beneath the furface’ 
of the earth. ‘Thus the particles which - 
form gezerated animal _embryons are 
prepared from dead organic matter by the _ 
chemico-animal procefles of fanguification. 
and of fecretion ; while thofe whieh form | 
Spontaneous micro{copic animals or microf- 
copic vegetables are prepared by chemical 
difo'utions and new combinations of ot-- 
ganic matter in watery fluids with fufh- 
cient warmth 1°” 
Some microfeopic animalcules are faid 
to remain dead for many days or weeks, 
ya when 
‘¢ There hence appears to be. 
an analogy between generation and nutri- 
