MR SAVILLE KENT ON SPONGES. 65 



Protozoa, This does not involve, however, that Sponges are 

 Metazoa, in the ordinary sense. Butschli, Sollas and lately Delage 

 are of opinion, on different grounds, that Sponges belong to a 

 separate phylum. My opinion is, that if we HAVE to classify, we 

 must either bring them to a separate group of the same value as 

 the Metazoa, or consider them as Metazoa, but forming a separate 

 Class, like Coelenterates, Echinoderms, etc. 



I have just published, in collaboration with my friend Pekel- 

 haring, a paper in which we draw attention to the fact, which may 

 be of value for classification, that in Sponges the cells seem not 

 connected in a way so as to enable them to conduct stimuli from 

 one cell to another, in other terms that they are destitute of the 

 principle, the significance of which culminates in nervous tissue. But 

 this is a mere suggestion, and I repeat once more, that / believe 

 we cannot yet answer the question about the position of Sponges. 



Dr Vosmaer was followed by Mr Saville Kent, who said : — 



It being desirable, I presume, that this sponge question should 

 be examined and discussed from every available standpoint, I would 

 crave leave to advocate a re-opening and fuller investigation of the 

 problem in association with its formerly-propounded, but for a long 

 time practically-abandoned, Protozoic interpretation. 



It is now some 16 or more years since, when making a particular 

 study of the Infusoria, that I devoted a little attention to sponge 

 organisation. It was about this time that the late Prof. H. James 

 Clark, of Boston, U.S.A., made known his discovery of a hitherto 

 undescribed modification of the Flagellate order of the Protozoa, 

 whose most important distinction consisted of the possession by 

 its members of a remarkable hyaline funnel-shaped extension of 

 the sarcode substance which encircled the base of the flagellum. 

 This structure he appropriately named the collar, and gave to the 

 Flagellate Protozoa that possessed it the title of collared monads. 

 Concurrently with the description of this species, Prof Clark 

 announced that he had found that the flagelliferous cells that line 

 the interstitial cavities of the various sponges he examined were 

 similarly constituted, and on these grounds he maintained that 

 sponges must be regarded as aggregated colony-stocks of collared 

 monads. The observations recorded by Prof. Clark were to a 

 large extent confirmed in this country by Mr Carter. A similar 

 confirmation attended my own investigations in the same direction, 

 and I was also fortunate in adding very considerably to the number 

 of four species only that were originally recorded by Mr Clark. 

 The late Prof Stein almost concurrently published a monograph 

 of the flagellate Infusoria, which also included several newly- 

 discovered collared types. 



It fell to my lot to have the privilege of first interpreting the 

 true nature and function of the hyaline collar-like structure that is 



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