of Foramini feral Structure. Ifio 



tinual circulation of <^ramilur particlo.s tlirou^liout the viscid 

 suljstancc of tlie body and its extensions. This order consists 

 of the Foraininifcni and the Gromida. 



" II. Radiolaria. — Incipient differentiation of the proto- 

 plasmic substance into endosarc and ectosarc, the fijrmcr semi- 

 fluid and fi^ranular, the latter more tenacious and pellucid ; 

 a nucleus and contractile vesicle; pseudopodia rod-like, tapcrint^ 

 from biuse to ])oint, composed of the same substance as the 

 ectosarc, exhibiting little disposition either to ramify or 

 coalesce, although a movement of particles adherent to their 

 exterior is often to be distinguished. The type of this order 

 is Actinophrys. 



" III. LOBOSA. — More complete differentiation of the proto- 

 plasmic substance into endosarc and ectosarc, the former being 

 a slightly viscous granular liquid, and the latter approaching 

 the tenacity of a membrane ; a nucleus and contractile vesicle ; 

 pseudopodia few and large, being in reality lobose extensions 

 of the body ■which neither ramify nor coalesce, having well- 

 defined margins, and not exhibiting any movement of granules 

 on their surface, the circulation in their interior being entirely 

 dependent on the changes of form which the body undergoes 

 as a whole." 



As regards those ^^ fundamental potentialities of each type'''' 

 — which, according to Dr. Carpenter, find a much more accu- 

 rate physiological expression in the " form, proportions, and 

 general arrangement of the pseudopodial extensions " than in 

 the definite step-hy-step advance from tlie simplest condition 

 of the body-substance, observable in the Foraminifera (in 

 which there is only the faintest foreshadowing of any thing 

 akin to reproductive organization*), to the intermediate stage, 

 in whicli tliis foreshadowing shows itself in the shape of a 

 centralized but still imperfectly aggregated mass, and, finally, 

 to the highest stage, in which the reproductive gemmules 

 assume the concrete form of a distinct specialized nucleus (the 

 culminating point being marked, at the same time, by the 

 association of the nucleus with a specialized respiratory organ, 



* It was shown by me that the '' yellow cellules " of MM. Clanarede 

 and Lachniann, or more or less colourless homologues of these " cellules," 

 occur in the sarcode of all the Rhizop')ds without exception, that in the 

 lowest order they are formed, as it were, from minute granules imifonnly 

 distributed in the sarcode, that in the second and third orders they are 

 formed by the splittin<r-up of the nucleus (which is in these a specialized 

 reproductive organ), but that in all three orders they constitute the 

 tnrcobldsi, or, in other words, the earliest visible embodiment of the 

 young organism. See Ann. & Mag. Nat. Hist., June ]86.'3 (where these 

 bodies are figured), Dec. 186.3, March 18G4 ; and Quart. Journ. Micr. 

 Science, July I8G0. 



