GLOSSARY OF TECHNICAL TERMS. 873 



PrOTOPHYTES. Gr. protos, first ; phuton, a plant. Organisms lowest in the scale of 

 the vegetable kingdom, having an essentially unicellular composition. 



Protoplasm. Gr. protos, first; plasma, what has been formed. The physical basis of 

 life, or elementary formative matter of all organic tissues. 



Protozoa. Gr. protos, first ; zoon, animal. The simplest, unicellar, animals. 



PSEUDOPODIA. Gr. pseudes, false ; podes, feet. Prolongations of the sarcode substance 

 of the body of Rhizopods and other Protozoa, which subserve the purpose of locomo- 

 tive appendages or feet. 



PULSELLUM. Lat. propello, pulswn, to push or drive. Term conferred by Ray Lan- 

 kester on that modified form of flagellum chiefly characteristic of Spermatozoa, but 

 possessed by some few flagellate Infusoria, whose action serves to drive the body 

 backwards through the water. 



Racemose. Lat. racemus, the stalk of a cluster of grapes. Having a clustered form of 

 growth, like grapes. 



Reniform. Lat. rents, a kidney ; forma, shape. Shaped like a kidney. 



Revolute. Lat. re, back ; volvo, I roll. Rolled back upon itself. 



Rhizopoda. Gr. rhiza, root ; pous, a foot. That group of the Protozoa whose loco- 

 motive organs take the form of extensile root-hke processes, or pseudopodia. 



Rhythmical. Gr. rlmthmos, measured motion. Denoting the regular pulsations of an 

 organ such as the contractile vesicle of an Infusorium. 



Rotulate. Lat. rotiila, a wheel. Wheel-shaped. 



Sarcode. Gr. sarx, flesh ; eidos, resemblance. The simple glutinous matter which 

 constitutes the chief body or vital mass of all Protozoa. 



Sarcolemma. Gr. sarx, flesh ; lemma, skin. The delicate investing membrane of 



muscular fibre. 

 Set^. Lat. seta, a stiff hair or bristle. The stouter bristle-like cilia possessed more 



abundantly by the Hypotrichous order of the Ciliate Infusoria. 

 Shagreened. Fr. chagrin, skin of a shark. Having a roughened consistence like 



shark-skin. 

 SiGMOlDAL. Gr. letter s ; eidos, resemblance. Having a shape resembling the letter S. 



SiLicious. Lat. silex, flint. Partaking of the nature and qualities of silica ; composed 



of flint. 

 *' SoiE DE Lachmann." Name conferred by Claparede upon the oral seta of the Vorti- 



cellidce, here distinguished as the vestibular seta. 

 Spatulate. Lat. spatula, a broad blade or slice. Having a broad blade-shaped 



outline. 

 Sporangium. Gr. spora, seed ; anggos, vessel. The spore-capsule or spore-receptacle 



of the Mycetozoa. 

 Sporiparous. Gr. spora, seed or spore ; pario, I produce. Producing spores. 



Stolon. Lat. stolott, a lax traihng branch. The procumbent adherent basal region of 



the colony-stock of such a type as Dendrosotna. 

 Swarm-gemmule. Name appHed by the author. Vol. i. p. 183, to the so-called ciliated 



sponge-larvce, and maintained by him to represent not individual germs or larvae, but 



ovate aggregations of typical collared monads. 



Stylate. Gr. stulos, a pen. Having a pointed stalk, or style-like character. 



Syncytium. Gr. j-w;/, together ; kutos, cell. Term applied by Haeckel to the hypothetic 

 ectodermal layer of a sponge, and in which, according to his interpretation, the cells 

 are indistinguishably fused with one another, their respective nuclei alone being 

 visible. Such a potential, though unsubstantial, multicellular structure is most nearly 

 reahzed in the Opalina and other multinucleate Infusoria. 



