and viviparous Production. J29 
flowly. After this, its Size and Motion be¬ 
comes every Day more confpicuous, its fpi- 
ral Revolutions diew themfelves more dif- 
tindtly, its Form becomes more perfect, a 
Shell, unconceivably delicate, is produced 
.over its tender Body % it now occupies a con¬ 
siderable Part of the Egg, turns itfelf vigo- 
roufly, and even creeps within it, and in due 
Time breaks it, and iffues forth. 
’Tis not unlikely this is Nature’s conftant 
and regular Courfe in the Produdtion of all 
Creatures that are oviparous; and that fhe 
proceeds nearly in the fame Manner to pro¬ 
mote the Growth and Birth of the Embrio 
in the Human Race, as well as in all other 
Creatures that we term viviparous, feems to 
me 'no lefs probable. 
After this Digreffion, which I was infen- 
fibly led into, 1 return to take Notice, that 
the Eggs which the Drawing exhibits were 
about a Fortnight old ; at which Time the 
young Snails were of fuch Size, in Propor¬ 
tion to the whole Room contained within 
the Eggs, as thofe marked c } c , c , may pret¬ 
ty nearly iliew. 
The other aquatic Animalcules reprefent- 
ed as hanging about this Parcel of Eggs, are 
no other than what were really found adher¬ 
ing to it when it was viewed by the Micro- 
fcope: and they were exactly htuated as in 
the Pi&ure, which was taken without the 
lead Exaggeration. Their extreme Minute^ 
nefs 
