SPONGES. i;37 



naturalists, find echoed from the one to the other, 

 so as to have gained admission, without being 

 questioned, in all the recent systematic works on 

 Zoology. 



The alleged spontaneous palpitation of the flesh, 

 occurring in particular parts, had its origin in the 

 views taken of the nature of sponges by Marsigli, 

 an Italian naturalist, who, in the year 1771, 

 announced that he had seen movements of dilata- 

 tion and contraction in the round apertures visible 

 on the surface of sponges. This statement, so con- 

 fidently advanced, seems to have made a strong 

 impression on Ellis, who, while pursuing a similar 

 train of observations, came to persuade himself that 

 he could see, not only the movements described by 

 Marsigli, but also the passage of water to and fro, 

 through the same apertures. He communicated 

 this account to the Royal Society in 1765; it was 

 published in its Transactions,* and will ever remain 

 an instructive proof of the degree in which our very 

 perceptions may be influenced by preconceived 

 views, and by the force of the imagination. Pallas 

 immediately admitted, without examination, the 

 hasty assertion of Ellis into his " Elenchus Zoophy- 

 torum ;" whence it was copied by succeeding 

 authors ; and the error became at length so widely 

 disseminated, that for more than half a century it 

 was received as an established fact in natural 

 history. The more accurate researches of Dr. 

 Grant on these subjects have at length dispelled the 

 prevailing illusion, and have clearly proved that the 

 sponge does not possess, in any sensible degree, 



* Vol. Iv. p. 284. 



