INFUSORIA. 



[ 422 ] 



INJECTION. 



Order HI. Cilio-flagellata. PEBIDININA. 



/The two portions of the cara- r Carapace with prolongations 1. Genus Ceratium. 



A transverse groove < P ace e 1 ual in "**& \ Carapace without appendages 2. Genus Peridinium. 



) f Borders of the notch turned up and 



{ The two portions unequal 4 lamelliform 3. Genus Dinophysis. 



-K, _,.,. I Borders not turned up 4. Genus Amphidinium. 



.No groove. Cilia on the anterior margin 5. Genus Prorocentrum, 



Kent arranges the Infusoria thus : 



* FLAGELLATA. 



t Ingestion by all the aurface. 



Order 1. Trypanosomata. A rudimentary fla- 



gellum, and an undulating membrane. 

 Order 2. Rhizojlagellata. A flagellum and lo- 



bate pseudopodia. 



Order '6. Radioftagellata. A flagellum and ra- 

 diate pseudopodia. 

 Order 4. Flagellata Panstomata. Flagella the 



only motile organs, 

 tt Ingestive area anterior. 



Order 5. Choano-flagellata, A flagellum and a 



collar, 

 ttt A distinct mouth. 



Order 6. Flagellata Eustomata. A flagellum 



only. 

 Order 7. Cilio-flagellata. A flagellum and cilia. 



** CILIATA. 



Order 1. Holotricha. Cilia all over the body, 



uniform. 

 Order 2. Heterotricha. Cilia general, but the 



oral larger. 

 Order 3. Peritricha. Cilia forming a spiral or 



circular wreath. 

 Order 4. Hypotrocha. Cilia ventral. 



*** TENTACUMFERA (Acinetina.) 

 Order 1. Suctoria. 

 Order 2. Actinaria. 



Kent defines 79 families, and 359 genera ; 

 of which our space will only allow a sketch 

 under the respective heads. 



BIBL. Miiller, Animak. infusoria, 1786 ; 

 Ehr. Infusionsth. ; Dujardin, In/us. ; Pi- 

 neau, Ann. So. Nat. 3 ser. iii., v., ix. ; Stein, 

 In/us. ; Focke, Isis, 1836, and Physiolog. 

 Studien-, Meyen, Matter's Archiv, 1839; 

 Pritchard, Infusoria ; R. Jones, Ann. N. If. 

 1839, iii.; Erdl, Mutter's Archiv, 1841; 

 Griffith, Ann. N. H. 1843, xii. ; Siebold, 

 Vergl. Anat. ; Cohn, Sieb. u. Koll Zeitschr. 

 iii. 260 ; Kolliker, Sieb. u. Koll. Zeitschr. i. 

 198 ; Claparede and Lachmann, Etudes, 

 Geneve, 1868; Engelmann, Inftis. 1862; 

 Jules Haime, Ann. Sci. Nat. s. 3. t. xix. 

 109; Clark, Boston Mem. N. H. 1866; 

 Balbiani, Sexual Org. of Infus., Q. M. J. 

 1862, 176, 285 ; Ann. N. H. 1858, i. 435 ; 

 Perty, Die kleinsten Lebensformen (new 

 genera and species], 1852 ; Cienkowski, Qu. 

 Mic. Jn. v. 96; Lieberkiihn, Ann. N. H. 

 1856, xviii. 319; Carter, ibid, xviii. 115; 

 Gosse. Jn. Mic. S. 1857 ; Ray Lankester, 

 Qu. Mic. Jn. ; Diesing, Prothelm. 1865; 

 Engelmann, Geqenbaur's Morph. Jahrb. 

 1876; Fromental, Microzoaires, 1876 ; All- 



man, M. M. J. xiv. 171; Hackel, Jen. 

 Zeitschr. 1873, vii. 516 (morphol} ; ibid. 561 

 (new marine} ; Butschli, Arch. mikr. An. 

 1873, and Zeitschr. wiss. Zoo/. 1878, xxx. 

 205; Simroth, Sch. Arch. 1876, xii. 51 

 (locom. appar.) ; Gruber, Zeitschr. wiss. 

 Zool. 1879, xxxiii. 439 (Jn. Mic. S. 1880, 

 282); Certes, Comp. rend. 1880, xc. 77 

 (glycogenesis in) ; Dallinger, Jn. Micr. Soc. 

 1880, iii. ]. 



INFUSORIAL EARTH. The fossil 

 deposits of Diatoinaceae were formerly so 

 called. 



INJECTION. The art of filling the 

 vessels and other minute tubular organs of 

 animals with coloured substances, by which 

 their relative size, arrangement, and relation 

 to the surrounding parts may be made ma- 

 nifest. The substances used for injections 

 consist of powders, mostly insoluble, mixed 

 with some liquid which holds them in sus- 

 pension or solution ; and while in this state 

 they are driven into the vessels by a syringe 

 or some similar contrivance. We shall first 

 give a sketch of the apparatus requisite, and 

 the method of making the liquids for in- 

 jecting the tissues of the Vertebrata, before 

 treating of the process itself. 



Syringe. Two or three syringes are requi- 

 site, of various sizes, adapted to the volume 

 of injection to be thrown into the vessels, or 

 the size of the animal or part to be injected. 

 In general, one holding 6 drms. or 1 oz., 

 and another holding about 2 oz. will be 

 found the most useful. Each syringe must 

 be provided with two rings at the upper 

 part next the handle, so that it may be 

 lirmly and easily held. The syringes when 

 in use should be surrounded by a roll or 

 two of flannel fastened with string, to pre- 

 vent their rapid cooling ; and the flannel 

 should be kept as dry as possible during the 

 process. 



Sometimes a much smaller syringe, called 

 an oyster-syringe, is useful for injecting 

 very small and soft animals. 



The plug of the piston is adapted to the 

 tube of the syringe by two pieces of wash- 

 leather, the method of replacing which must 

 be learnt at the time the syringe is bought, 



