HISTORY OF ZOOPHYTOLOGY. 17 



was he afterwards satisfied of the non-existence of animalcules, 

 that he combated the opinion of those who maintained the con- 

 trary, pointing out where the error lay in mistaking small in- 

 sects which had crept into the sponge in search of food or shel- 

 ter for the real inhabitants and fabricators of the zoophyte. Yet 

 not the less was Ellis convinced of its animality ; — its chemical 

 constituents and its structure were to him conclusive proofs of 

 this fact, particularly when added to the signs of irritability he 

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

 he writes to Linnaeus, " thejihroi 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 ani- 

 mal, 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,-}- Linnaeus was in the 



• 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 Alcy- 

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

 Peyssonell's account of them, which is printed in our Philosophical Transac- 

 tions, wherein he pretends to tell you, that he takes the anirn;d out of them, that 

 forms them ; and that he put it into them, and it crept about through the mean- 

 ders 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 polype-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) con- 

 firmed 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 observe 

 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. p. 79-80. 

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



B 



