ADVANCE IN LOWER PLANT AND ANIMAL FORMS 179 



PLAT15 LXXV {amtinmil) 



Figs. 10 ami 11. — Extended and contracted zooid ((MytridM scutellum), x 360 (Cohn). Bod}' oblong, flattened, pointed anteriorly, 

 rounded posteriorly and highly retractile; peristome-fleld extending back third of body; posterior portion of body furnished witU 

 transverse row of twelve slender anal styles. Illustrates the centrifugal and centripetal movements seen in the lower animal forms 

 (the Author). 



Fig. 12. — Adinotricha saltans as figured by Cohn, x 360. Body elliiitical and equally rounded at both ends, five large styles 

 radiating from anterior border ; peristome and adoral cilia produced backwards one-third of body ; small styles occur on latero- ventral 

 and posterior portions of body. 



Fig. 13. — Diagrammatic longitudinal section of Oxytricha pellioiiella, x 400. ad, Adoral ; fr, frontal ; v, ventral ; an, anal ; and t', 

 dorsal cilia or setse (Sterki). 



Fig. 14. — Ventral aspect of same as drawn by Stein. 



Fig. 15. — Fixed adult animalcule {Aciiieta ati/Unfa) seizing another animalcule, x 1000. Lorica subpyriforni, its cavity terminating 

 interiorly in short, hollow stalk-like attachment ; its lateral walls at points of exit of tentacles produced outwards in fine radiating 

 tubuli ; contained body stellate; the tentacles, which vary from six to twelve, capitate; contractile vesicle (cv), single ; nucleus (»), 

 spheroidal and subcentral. Illustrates the power possessed by animalcules of seizing and transmitting food into their bodies by tentacles, 

 psendopodia, &c. The food is dniwn into the body by centripetal movements ; it is seized by centrifugal movements. In the one 

 case the sarcode is projected out of the body against the prey; in the other it is drawn into the body by an opposite and counter 

 movement (the Author). 



Figs. 16 and 17. — Encysted examples of same with body (Fig. 16) divided into two halves. 



Fig. 18. — Normal adult zooid (Spheerophrya urostylse) with suckers, x 200 (Stein). 



Fig. 19. — The same dividing by transverse fission ; the anterior part provided with suckers and temporary cilia not shown. 



Fig. 20. — A similar zooid elongated and with cilia and suckers developed preparatory to subdivision, x 200 (Stein). 



Fig. 21.— Sphxmplmja pusilla, x 150 (Claparede and Lachmann). Body minute, spherical, bearing a ^■ariable number of short, 

 widely scattered suckers. Nucleus ovate ; contractile vesicle single. 



Figs. 22, 23, and 24.— Animalcules (Sphxrophrya stentorea), x 200 (Stein). Bodies illoricate, more or less spherical in form, with 

 delicate capitate suckers scattered irregularly throughout the periphery ; freely swimming ; no fixed pedicle. 



Fig. 25.— Zooid (Stichotricha secunda) projecting from its mucilaginous sheath, x 250 (Stein). Body very active, lanceolate- 

 fusiform, tapers markedly anteriorly and less posteriorly ; peristomal or adoral cilia longest at anterior extremity, diminishing as oral 

 aperture is reached ; ventral setje short, marginal sets" long and slender. Anterior half of body projected from mucilaginous sheath 

 to right in screw-like manner. Animalcule not unfrequently leaves its sheath and swims freely in the water. 



Fig. 26.— Adult zooid (Podocyathus diadema) with its tentacles retracted, x 300. Lorica cup-shaped, transparent, and of very 

 delicate consistence, rugose or wrinkled transversely ; pedicle slender, flexuose ; suctorial tentacles few, short, occupynig central 

 position; circumjacent prehensile tentacles numerous, extensile to twice the length of diameter of body, their substance finely granular. 



Fig. 27.— Vermiform zooid {Ophnjodendron belgicum), x 400 (Fraipont). Body subcylindrical, seven or eight times as long as 

 broad, attached posteriorly by sessile pedicle. 



Fig. 28.— Sessile zooid (Ophryodendron multicapitatum) bearing four proboscidiform organs with transverse markings, x 300 (W. 

 S. Kent). Body ovate, subspherical or pyriform, pedicellate when young, sessile in adult state, adult zooid supporting as many as four 

 subterminally developed proboscidiform organs, whose distal extremities bear from thirty to forty cirrhose appendages. 



Fig. 29.— Distal region of zooid (Aciiieta vorticelloides) showing rudimentary development of the lorica x 300 (Fraipont). Body 

 subspherical; tentacles developed throughout exposed peripheral surface, extensile to length equal to diameter of body; lorica 

 rudimentary, consisting of small cup-shaped expansions only of distal extremity of supporting pedicle. Nucleus (»), ovate ; contractile 

 vesicle (cv), single and of large size. 



Fig. 30.— Distal extremity of pedicle bearing animalcule (Hemioplmja gemmipara) with extended tentacles of two orders, suctorial 

 and prehensile ; the latter spiral in their nature, x 400 (Hertwig). Body contractile and variable in form, u,sually cup-shaped, widest 

 anteriorly, narrow where it joins pedicle; tentacles projected in crown-like fashion from entire anterior border, the suctorial ones 

 subcentrally developed, usually five or six in number and short, the prehensile ones being three or four times more numerous and 

 longer. The external surface of the latter are also granular in a spiral direction. Pedicle longitudinally and transversely striate ; 

 contractile vesicle (cv) two or more in number ; nucleus usually scimitar-shaped. Spiral character of prehensile tentacles illustrated 

 at Figs. 33 and 34. 



Fig. 31.-Zooid (Sph^rophrya magna) having seized and in the act of devouririg by suction half-a-dozen examples of Colpoda 

 parvifrons, x 300 (Maupas). Body spherical ; tentacles distinctly capitate not exceeding fifty m number ; length equal to diameter of 

 body, produced from all parts of periphery. Resemble in function the suctorial arms of the star-fish (the Author). 



Fig. 32.-Adult zooid (Hemiophrya truncata), x 250 (Fraipont). Body elliptical or subquad.angular; pedicle massive and 

 irregular, three or four times length of body, same thickness as lower part of body and tapering to point of attachment its distal end 

 arti^ulat^ or transversely plicatef suctorial tentacles develop from centre of distal region of body, the prehensile tentacles (fifty or 

 sixty in number) more slender and prolonged than suctorial ones, round which they form a fringe. 



Fig 33 -Tentacle of zooid (Acimtopsis rara) in the contracted condition and highly magnified, showing externally developed 

 spiral fibrilla, x 600 (Robin). Tl e proboscidiform tentacle is in this case very attenuate, or fihform when extended its length then 

 eSiJalling five or six times that of the body, exhibiting throughout when contracted an exteriorly developed, very delicate, plicate, 

 spiral fibrilla. The tentacle is structurally and functionally spiral and very remarkable. 



Fig. 34.-Tentacle of a normal zooid (Podophrya elmgata) in a state of f'^^raction, highly njagmfied, and exhi^^^ 

 convolute aspect due to the presence of a superficial spirally developed granular crest or film, x 800 (W.S Kent . The configuration 

 S t^Bntrcles seenin Figs 33 and 34 is analogous to that'witnessed in the spirally disposed fibrilla of the stalk of a vorticelhx. The 

 gmce and rapidit^of the m^^^^^^ of the latter baffle description. They must be seen and .studied m order to be even partially 



realised. 



