164 Mr. W. Clark on the recent Foraminifera. 



clined to think there are longitudinal vessels attached to the 

 walls of the common canal to supply some of these functions, 

 particularly that to administer, in conjunction with the capillary 

 filaments, the oxygen. I do not believe there is a circulation be- 

 yond that of flotation, arising from nervous contraction — I say 

 nervous, because I shall presently enunciate the reasons for using 

 this term. The respiration is effected by the very fine capillary 

 filaments which issue from the foramina of such of these animals 

 that have them, and which have been named " pseudopodia," or 

 "pedes spurii f the filaments are only protruded from the last- 

 formed chambers, which, until new ones are constructed, consti- 

 tute the limits of the respiratory apparatus, the preceding ones 

 being closed by the exudation of calcareous matter from the en- 

 veloping membrane of each lobe, and though the punctures of 

 former foramina are always seen, they are imperforate. The 

 sustentation of these animals is undoubtedly the minute animal- 

 cule received through the orifice into the common canal — the 

 eight tentacula prove this — and are there digested, and the nutri- 

 tive fluids enter probably by absorption into each mass of paren- 

 chyme, the rejectamenta being discharged by the aperture. 



On the question of the nervous aud muscular influences, which 

 Lamarck only admits, as independent of sensation and interior 

 sentiment, in his apathetic animals, amongst which are the Po- 

 lypi, I must be allowed to make a few observations, to explain 

 my reasons for not concurring in the views of that great natu- 

 ralist. Lamarck contends that sensation, or interior sentiment, 

 does not exist in the lower animals, and that in them all move- 

 ments arise from irritabilities excited by external impressions : I 

 demur to this doctrine, and firmly believe that no created being 

 can exist and exhibit evidences of vitality, by motion, without 

 having implanted in it a certain degree of sensation or interior 

 sentiment, by the influence of which the nervous and muscular 

 powers are put in action. I grant that external causes may pro- 

 duce motions and contractions, not I think by exciting an irrita- 

 bility independent of sensation, as Lamarck terms it, but by the 

 agents and after the manner I have just stated. 



It will be admitted that the sensations in the lower animals, 

 which are the origin of the nervous and muscular influences, are 

 of the most subdued qualities ; and though their points of de- 

 parture, and the muscular supports dependent on them, may not 

 be discernible by the most powerful instruments, still I believe 

 that they exist, and produce those movements which are observed 

 in the monad as well as in man. In the superior and larger ani- 

 mals, we can perceive the causes of these influences and admit 

 their existence, because they are apparent ; and why not in the 

 smallest, though they escape our vision ? In the nearest fixed 



