g°02 ANIMAL REPRODUCTIONS, 
‘tenacious operculum which is produced by 
* vifcous matter that they generate. By this 
© they are defended from external injury ; but it 
‘ is not more advantageous to them than detri- 
* mental to one defirous of viewing them for ac- 
“ curate obfervation. To do fo, I have always 
« endeavoured, as much as poflible, not to aggra- 
* vate the effects of fuch an immenfe wound as 
© they have received, by any additional irritation, 
* fuch as breaking the fhell behind, and fome- 
“times, if obftinate to appear, pricking them, 
‘which are not the actions of a mafterly hand, 
‘ or of one accuftomed to fimilar experiments ; 
‘and it is actually not uncommon, that thofe 
¢ ftimulated in this manner die. But, to accom- 
¢ plith my object, I endeavour to entice them 
‘ out, fo that they may appear fpontaneoufly, 
© which has always fucceeded on putting them in 
‘warm water, or expofing them to the {oft 
‘ fhowers of {pring or fummer ; then they are na- 
* turally induced to come into the open air. 
‘ In thofe deprived of the large horns, or one 
“ half, 1 have never obferved any thing new for 
« ten, fifteen, even twenty days, nay, moft com- 
‘monly a month. In the place of amputation, 
* a globule arofe, which, becoming larger in time, 
‘ exhibited a black point in the centre, exaétly 
‘ correfponding to that in the original horns. 
§ Two and more frequently three months haye 
§ elapfed 
