'SQ4 My. H. ,f. Carter on the (Jirronn .Appendages 



uperma (lig. l,f)j is still lunger than that in C. latitentaj 

 whieh, on the other hand, comes from the State of Pennsyl- 

 vania ; but the cirri themselves, although more numerous, are 

 so reduced in size as to a])pear to be aborted when compared 

 with those of the other species (tigs. 7,^, and 8, h). 



I have noticed, on this occasion, that the inamilliform 

 })rocess opening into the tubular prolongation of the chitinous 

 coat is not given off from the latter, as represented in C 

 tenospenna ('Annals,' /. c. tigs. 1, e, and 2, e, &c.), but ap- 

 pears to belong to the extremely thin membranous envelope 

 of the germinal contents (PI. XIV. fig. 2, e, &c.). The cir- 

 cular ruga3 which are on the cirrus of C tenosperma (' Annals/ 

 /. c. fig. 2, g) I have not seen. 



Of course, there is much variety in the growth of the 

 cirrous appendages in Siwugillctj since they could hardly belong 

 to a sponge if this were otherwise : thus they may be very 

 long, round, and whip-like, as in C. tenospenna (' Annals,' 

 /. c. fig. 1, g gg), or ribbon-like, as in C. latitenta (PI. XIV. 

 fig. 2, g g g)t or very small and in greater or less plurality, as 

 in G. tuhlsperma (figs. 7 and 8) ; or there may be supernume- 

 rary ones in the form of buds, as in 6'. latitenta (fig. 4, ee), 

 or branched and anastomosing reticulately towards the free 

 termination in the same species (fig. 5) ; or there may be a 

 double set of cirri on ihe tubular prolongation, one below the 

 other, as in C. tubisperma (fig. 9) ; or in the same species the 

 tubular prolongation may be double or perhaps in greater 

 plurality, arising probably from there being more than one 

 liilous aperture on the statoblast, which is not unfrequently 

 the case (fig. 10, e, h) ,• and so on, endlessly ; but the fore- 

 going instances are sufficient for our purpose. 



Nothing can be more opposed to the advancement of natural 

 history than burdening it with species wdiich involve subse- 

 quent contradiction, as nothing is more true than that the 

 impression of '^ bitter words " once spoken can never be entirely 

 efi'aced ; after which, to myself, nothing is more pusillani- 

 mous than assigning functions to developments which speak 

 for themselves, as if Nature could not do without them. 

 Hence 1 have only alluded to the " otfice " of the cirrous 

 appendages on the statoblast of certain species of Spwngillaj 

 which seems to me so plain that a child could point it out ; 

 yet if we were asked, why they are not in all species of Spo7i- 

 gilla, or on the statoblasts of all species of freshwater Polyzoa, 

 or why the " Galloway breed of cattle " has no horns, it is not 

 inipiubablc that either question would be met with an " opinion " 

 which is more a matter of faith than of scientific inquiry. 



