422 HISTORY OF ZOOFHYTOLOGY. 



out where the error lay in mistaking small insects which had 

 crept into the sponge in search of food or shelter for the real 

 inhabitants and fabricators of the zoophyte. Yet not the less 

 was Ellis convinced of its animality ; its chemical constitu- 

 ents and its structure were to him conclusive proofs of this fact, 

 particularly when added to the signs of irritability he saw some 

 species exhibit when in a fresh state. " I am persuaded," 

 he writes to Linnseus, "the fibra intertextce of sponges are 

 only the tendons that enclose a gelatinous substance, which is 

 the flesh of the sponge. Mr. Solander and I have seen the 

 holes or sphincters in some of our sponges taken out of the 

 sea, open and shut while they were kept in sea-water ; but 

 discovered no animal like a polype, as in the Alcyonium 

 manus mortui." And again : " I attended last summer in 

 pursuit of the animals in sponges, but believe me there are 

 none : but the whole is an animal, and the water passes in a 

 stream through the holes, to and fro, in each papilla."* 



When Ellis published these discoveries, which form in fact 

 an epoch in the history of natural science,-f- Linnaeus was in 



* Lin. Corresp. vol. i. p. 161 and p. 163. In a subsequent letter Ellis explains 

 himself more fully. " I am now looking into the nature of sponges, and think, by 

 dissecting and comparing them with what I have seen recent, and with the Alcyonium 

 manus mortua, that I can plainly see how they grow ; without trusting to Peysson- 

 nell's account of them, which is printed in our Philosophical Transactions, wherein he 

 pretends to tell you that he takes the animal out of them, that forms them ; and that 

 he put it into them, and it crept about through the meanders of the sponge. This 

 kind of insect, which harbours in sponges, I have seen ; but sponges have no such 

 animals to give them life, and to form them. Their mouths are open tubes all over 

 their surfaces, not furnished, like the tubes of the Alcyonium manus mortua, with po- 

 lype-like mouths or suckers. With their mouths they draw in and send out the 

 water ; they can contract and dilate them at will, and the Count Marsigli has (though 

 he thought them plants) confirmed me in my opinion, that this is their manner of 

 feeding. If you observe what he has wrote on sponges in his Histoire de la Mer, and 

 the observations he has made on the systole and diastole of these holes in sponges, 

 during the time they are full of water, you will be of my opinion. Take a lobe of the 

 officinal sponge, and cut it through perpendicularly and horizontally, and you will ob- 

 serve how near the disposition of the tubes are to the figure I have given of the sec- 

 tions of the Alcyonium manus mortua in my plate of the Sea- Pens." Lin. Corresp. 

 vol. i. pp. 79, 80. 



t The Royal Society adjudged to Ellis the Copley medal, "as the most public 

 mark that the Council can give of their high sense of the great accession which na- 

 tural knowledge has received from your most ingenious and accurate investigations." 

 The medal was delivered to him, Nov. 30, 1768, by Sir John Pringle, the President. 

 Soland. Zooph. introd. p. xi. See also Swainson's "Discourse on the Study of Nat. 

 History," pp. 38, 39. 



