362 Dr, Baillie’s Account of a 
The human machine might have been conftrudled in this 
way generally, and under fuch circumflances what is now 
called the natural fituation of parts would have been as lingu- 
lar as the prefent phenomenon. 
There appears to be lefs variety in the nervous fyflem of 
animals of the fame fpecies than in moll parts of the body. 
There is fcarcely any difference in the appearance of the brain, 
and much lefs in the dillribution of the nerves than of the 
blood- veffels. 
There is alfo little variety in the organs of fenfe : perhaps 
the mechanifm in both thefe is nicer, fo that a confiderable 
deviation would interfere with their peculiar functions. 
The moll common great deviations which nature produces 
in the llructure of an animal are various kinds of monftrofity, 
by which the animal becomes often unfit for continuing its 
exigence. Why nature fhould in its greater deviations fall 
into a very imperfedl formation, much below the llandard of 
her common work, does not appear very obvious. 
It feems that there might have been many varieties where 
the fundtions could have been preferved. Perhaps it is with a 
view to check the propagation of great varieties, 1 o as to pre- 
ferve an uniformity in the fume fpecies of animals. 
It has been much agitated, whether monllrohties depend on 
the original formation, or are produced afterwards in the gra- 
dual evolution of an animal. 
This does not appear to be a queflion of much importance ; 
nor perhaps can it be abfolutely determined. But upon the 
whole it is more reafonable to think, that the fame plan of for- 
mation is continued from the beginning, than, that at any fub- 
fequent period there is a change in that plan. 
It 
