Mr. H. J. Carter on the Organization of Infusoria. 125 



That these cells in Plnnarin and Otosfoma are homologous 

 organs can hardly be doubted, both from their general characters 

 and their corresj)ondence in position ; but what their office may 

 be is at present unknown. Occurring, however, as they do, in 

 the stomach of Pliinaria and llotifera, where there is no other 

 analogue of the so-called biliary follicles of the lower worms*, 

 and being almost identical in Otostoma and Plunaria, they not 

 only ally these two organisms, but, at the same time, appear to 

 be the homologue of the biliary follicles in each. 



I have never seen any cells of this kind in Amoeba, unless the 

 "granules" already described be their analogues. It appears 

 evident that these are the same both in Amaba and the sponge- 

 cell, and that they are the seat of the green colour in the latter. 

 Are the green granules of the sponge-cell analogous to the parts 

 or cells respectively which hold the colouring matter or endo- 

 chrome in the Diatoinea, Closte)'ium, Spirogyra, Cladophora, &c., 

 and (through the latter) to the "green disks" or peripheral 

 layer of chlorophyll-bearing cellules in the internode of Nitella, 

 and those which, scattered irregularly through its moving pro- 

 toj)lasm, are circulated round the cell of Serpicula verticillata 

 (ligs. 03 a, 61 a) ? If so, the chlorophyll-bearing parts of the 

 protoplasm in vegetables may be the analogue of the liver in 

 animals. In some Ilotifera the spherical cells appear to bear 

 bile as green as grass or chlorophyll f, while in others it is 

 yellow. The same diversity of colour occasionally manifests 

 itself in the Diatomea ; while in Spirogyra especially, the oil- 

 globules and amylaceous dej)osits, which abound in abortive 

 conjugation, are entirely confined to the green spiral-bands, thus 

 corresponding, in one identically, and in the other transitionally, 

 with the fat and sugar which are formed in the liver of man; the 

 colouring matter in all of course being, when present, a mere 

 indication cd't.pur. of the nature of the organ. How the colour- 

 bearing cellulie of the s])hcrical cells are produced in Otostuma 



* By this I do not mean to class the Planaviaus with the Worms. Mr. 

 C. Giranl, who has followed out the " Embryonic Development of Plano- 

 cera ellipfica," would ally them to the Gasteropoda, — ' Researches upon 

 Nemerteans and Planarians,' 4to, Philadeli)hia, 1854. 



t Since writing this, I have seen Diylena r.atellina, Ehr., discharge the 

 gixen matter from its alimentai-y canal, and retain nothing but the ordinarily 

 coloured biliary cells ; also D. cauduta to have the whole of the soft tissues 

 of its body coloured in this way, unless there be diverticulations of the 

 stomach to this extent ; so that 1 now begin to think this coh)in , which at 

 first apjjcared persistent, to be adventitious, and gained from ihcEtiylence, 

 and. j)erhaj)s, chlorophyll-bearing ])rotoj)lasm on which these species chiefly 

 feed. Accidentally, i)erhaps, the bile may become green in any species of 

 Rotifera, as in animals generally ; and this appears to be the case with the 

 endochrome of DiafomecB. 



