102 Transactions of the Society. 



APPENDIX J. 



The Final Conclusions of F6lix Du.taedin. 



No apology is needed for a short recapitulation of the final conclusions 

 of Dujardin, recorded in the larger work cited in this Memoir (p. 41), 

 regard being had to the position which he occupies with regard to the 

 history of the Foraminifera. Recognizing, as he was the first to do, 

 that their zoological place was among the lowest forms of creation he 

 included them in his " Second Order. Rhizopoda. Asymmetrical 

 Infusoria ; 2nd Family. Am(ehae. Naked animals, crawling, of con- 

 tinually varying form. 3rd Family. Rhizopoda. Animals either crawling 

 or fixed ; secreting a more or less regular shell or test, from which 

 protrude continually varying expansions." 



It must be remembered that the period covered by the early work 

 of Dujardin was the era of the invention of the Achromatic Microscope, 

 and the revelations afforded by the new instruments seemed to con- 

 temporary biologists to open up a vista capable of the widest and 

 hitherto undreamed of expansion. Thus Dujardin says in his Introduc- 

 tion (p. vii), " Quoique le Microscope par les perfectionnements qu'il a 

 recus depuis quinze ans soit devenu en quelque sorte un instrument 

 nouveau et inconnu de nos predecesseurs, nous sommes loin de croire 

 qu'il soit arrive an terme de ses perfectionnements possibles," and after 

 some anticipations of possible progress he concludes (p. viii), " Comme 

 €elui qui batit sur le sable mobile on sur un sol inconnu, nous sommes 

 done expose a voir notre oeuvre, a peine edifice, s'ecrouler, ou perdre 

 tout d'un coup sa valeur, par suite de telle decouverte pressentie vague- 

 ment et qui doit multiplier un jour la puissance de notre vue." It 

 was actuated by such reflections as this that Dujardin himself laboured 

 at, and contributed not a little to, the improvement of the instrument. 



Accordingly he commences his work with the statement that " the 

 history of the Infusoria is entirely bound up in that of the Microscope." 

 His mind was much exercised by the nature of the protoplasm to which 

 he had given the designation " sarcode," and he observes (as others 

 have observed and recorded in varying terms) on p. 25, " Nevertheless 

 we are not justified in saying that, where the Microscope shows us only 

 a homogeneous transparent substance, but endowed at the same time 

 with movement and life, we must conclude with finality that neither 

 fibres nor organs of any kind are present. . . . We must arrive at tlie 

 conception of an ultimate expression of size at which a homogeneous 

 substance is of itself contractile." ^ He divides the Rhizopoda of 

 this third family (Foraminiferes) into : (1) Free, e.g. Rotalia, Poly- 

 stomella, and Cristellaria, of which the first has a test lined with an 

 internal membrane, the two latter being entirely calcareous and per- 



^ We may compare this with a passage in Carpenter's " IMental Physiology," 

 Liondon (1874), p. 44, in which he says, after describing the behaviour of certain 

 Foraminifera to which I have been bold enough to apply the term "purposive," 

 " The apparent absence of a nervous system is doubtless to be attributed in many 

 instances to the general softness of the tissues of the body, which prevents it 

 from being clearly made out among them." (See also Journ. R. ]Micr. Soc. (1916), 

 p. 138, in a paper in which I discussed this matter at some length.) 



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