[ 28s ] 
*'• plants (fponges) to‘ m^ke a compleat botanical 
c6lle6tion, with many curi’oiis rertiarks, which I 
have made on the fyftole and diaflole, which I 
have obferved in certain fmall round holes, when 
“ they are firft taken out of the fca j this motion 
** continues in them till the water they contain is 
entirely wafted away.’* 
Nothing can more clearly defcribe what I have 
feen in our fponges ; fo that, making an allowance 
for the then prevailing opinion that they were vege- 
tables, I think, he comes nearer the truth than Dr. 
Peyfonell’s account of the formation^ of fponges by 
little animals, that walk to and fro in the labyrinth 
of the tubes to conftrua: his extraordinary animal 
I come iiow to fliew you how near they approach . 
to the alcyoniums in their internal form and manner 
of growth. . , 
In order to explain this, I have given you the 
perpendicular and horizontal fedtions of the cornmon 
ofHcinal fponge ^ • becaufe this is in the power of moft 
gentlemen to examine. And, iii vol. LUl. ot the 
Philof. Tranf. Tab. 20. Fig. 10. c. A 1 1 and 13. 1 . 
have given the perpendicular and horizontal lections 
of the alcyonium mams marina^ both magnifkd 
and in the natural fize ; becaufe fpecimens of this 
kind are likcwife eafily obtained, being found in 
plenty on rocks and fhells near the Ifte of Sheppey, 
at the entrance of the river Thames. . , , 
You’ll obferve, the connected tubes of both anie 
from the part to which they adhere to the rocks, &c. 
From hence both kinds branch out and fwell into 
irregular lobes, with this difference, that the furface 
. * See Tab. X. fig. E and D. 
