14 Prof. H. James- Clark on the Animality of the Ciliate Sponges, 



From the time when Ehrenberg published his great work the 

 ' Infusionsthierchen/ to the period of the issue of the ^ feudes 

 sur les Infusoires' of Claparede and Lachmann, there has been a 

 steadily growing belief that a large part of that mass of ani- 

 malcules which Ehrenberg denominated Infusoria forms a dis- 

 tinct grand division, quite as decided in character as any of 

 the four great groups which are now generally accepted. Still 

 it is a little curious that, although Cuvier had long ago pointed 

 out the plan or type upon which his four embranchements were 

 constructed, later investigators have not attempted to elucidate 

 the typical idea which lies at the basis of the Protozoan organi- 

 zation. Claparede and Lachmann have approximated nearest to 

 such an attempt, in their division of a part of the group into 

 dexiotropic and Iseotropic sections; but nothing is said even by 

 them of a plan which runs through the whole grand division. 

 Surely they had seen enough of material, at least of the higher 

 divisions of the group, to sustain them in pronouncing upon the 

 typical relation of the Infusorial organization ; but it may be 

 that the apparent paucity of characters among the lower mem- 

 bers of this grand division misled them into an apprehension that 

 there was no definite taxonomical relationship of the organs. 

 That they recognized the latter as members of the same group 

 with the former, no one will deny; but it must be conceded that 

 the affiliation was observed to be only one arising from similarity 

 of organization and habit, and not from any community of plan 

 in tlie disposition of the organs. 



It is now over two years since I demonstrated (in a course of 

 lectures, delivered in February and March, 1864, at the Lowell 

 Institute in Boston) that the arrangement of the organization 

 of the Protozoa is based upon a spiral or, rather, a helix: more 

 recently those lectures have been published"^, and the type of the 

 organization of the Protozoa, as well as that of each of the 

 other four grand divisions of animals, made as clear by illustra- 

 tions as the limits of the volume seemed to allow. In order, 

 therefore, that I may not appear to claim for the Sponges merely 

 a new position in the universe of obscurities, I shall take the 

 liberty of drawing the reader's particular attention to the argu- 

 ments which I have adduced, in the volume above mentioned, 

 to prove the unity of plan in the organization of the Protozoa 

 and its dissimilarity from any other which dominates among the 

 four remaining grand divisions. 



This much being premised, I proceed now to give a sketch of 

 the peculiarities of some of the genera of Infusoria flagellata 

 with which I think the Sponges are most intimately associated. 



* H. James-Clark, * Mind in Nature.' D. Appleton & Co., New York, 

 1865. 



