242 ANIMAL REPRODUCTIONS. 
indicated by the afh-coloured line furrounding 
the neck. 
Here I fhould not negle& to obferve, that, in 
- the fame manner as fome {nails, deprived of half 
the head, never reproduced even in the longeft 
time,. the like has equally happened to feveral of 
thofe totally decapitated. Indeed, of four hun- 
dred and twenty-three mutilated in this way, 
thirty-two did not evince the {malleft rudiments 
of reproduction in a year ; ninety-three could not 
reproduce better: the heads of one hundred 
and forty-five were regenerated with monftrofi- 
ties ; and the remainder died. Reproduction of 
the whole head requires nearly the fame time as 
that of the half. , 
Should I be afked, why there is no reproduc- 
tion, either of the head or horns, in different 
{nails ? I fhall ingenuoufly confefs myfelf unable 
to advance any thing concerning it but. fimple 
conjeCtures. As the reproducing and unrepro- 
ducing {nails are both of the fame fpecies, we 
cannot fay that fome of them have the property 
and others have it not. I fhould rather fuppofe, 
that the reproductive virtue cannot take effeét 
from the difeafed {tate of the {nails ; having uni- 
formly. obferved, that, befides their moft remark- 
able emaciation, the exterior aflumes a yellowifh 
hue, which feems the infeparable concomitant of 
fnails affected by difeafe, and liable to perifh. 
After 
