[ 28o ] 
Received December 5, 1765. 
< 
XXXI. On the Nature and Formation of 
Sponges: In a Letter from John Ellis, 
Efquirey F, R. S» to Dr. Solander, 
F. R. S. 
S I R, 
Read Dec. ^ 9 >'\T O U, who ftudy nature in an eml- 
‘765- ^ degree, view her in all her 
works proceeding by regular gradations from the 
lowed; to the mod: perfeeft of all created beings among 
thofe animals commonly called Zoophytes, you 
may plainly dilcover an evident approximation, from 
the ruded; irregularly-formed fponge (which is the 
lowed being that 1 have yet obferved to have the 
appearance of animal life) to the mod beautiful and 
elegant red coral. 
The nature and formation of fponges having ne- 
ver yet been thoroughly invedigated, every attempt 
to explain this dark part of nature mud give fatif- 
fadlion to the curious. The intent, then, of this letter 
is to convey to the Royal Society, through your 
hands, what we have feen in the experiments we 
made on them at the fea fide ; the fubdance of what 
has been faid on the fubjedl by moderns as well as 
ancients ; and ladly, to fliew how nearly they ap- 
proach to the Alcyoniums, a clafs of beings next 
above 
