INJECTION. 



[ 428 ] 



INOMERIA. 



The tissues of the Invertebrata are so 

 soft, that the ordinary syringes and pipes 

 can rarely be used for injecting them, and 

 recourse must be had to a finer and lighter 

 form of apparatus. This may consist of a 

 fine trochar, with a needle. In using it, 

 the small vessel through which the injection 

 is to be thrown, is held with forceps against 

 the end of the trochar, and punctured with 

 the needle. The trochar is next directed 

 into the puncture, and the needle withdrawn. 

 The small nozzle of a syringe is then intro- 

 duced into the upper end of the trochar, 

 and the injection thrown in. A form pro- 

 posed by Harting consists of a common 

 glass pipette of moderate width, and of a 

 caoutchouc tube the smaller end of which is 

 fastened by means of thread to the broader 

 end of a fine, curved, glass nozzle. In using 

 this apparatus, the pipette is first filled with 

 the injection, and its lower portion intro- 

 duced into the broader end of the caout- 

 chouc tube, which, from its conical form, it 

 accurately closes. 



Different liquids for injection are also 

 usually requisite ; and many have been re- 

 commended. Among these may be men- 

 tioned : 1, indigo, triturated with oil and 

 diluted with oil of turpentine ; 2, oil-paints 

 diluted with oil of turpentine ; 3, infusion 

 of logwood (Hcematoxylori)^ ; 4, solution of 

 carmine in size or in ammonia ; and 5, solu- 

 tion of alkanet in turpentine. 



A considerable escape of the injection is 

 often unavoidable in these cases, and must 

 therefore not be heeded. 



Some injectors simply introduce the in- 

 jection into the dorsal vessel or lacunae, 

 whence it is propelled to all parts of the 

 body by the circulation. Thus Agassiz 

 says that if the indigo injection (1) be in- 

 troduced in this way into insects, it is seen 

 to circulate almost instantaneously in every 

 part of the body, and on subsequently open- 

 ing the insect all parts of the body are 

 found to be coloured. We believe that 

 Blanchard also adopts this method. Pro- 

 bably the best injections for this purpose 

 would consist of alkanet and turpentine. 



Injections may be preserved either in the 

 dry or wet state. For the former, sections 

 should be made, thoroughly dried upon 

 slides, then moistened with oil of tur- 

 pentine, and mounted in balsam. For pre- 

 servation in the wet state they must be 

 mounted in cells while immersed in dilute 

 spirit, Goadby's B. solution, or in chloride 

 of zinc (see PBEBEBVATION). 



We have not space to give a list of 

 injected preparations; they are all very 

 beautiful, but we can only 'notice a few of 

 the most interesting. For practice in the 

 art of injecting, we may recommend the 

 kidney of a sheep or pig, one system of 

 vessels being alone filled with red or yellow 

 injection ; and this should be the arterial. 

 Afterwards, in another kidney, the urinary 

 tubules may be injected first, with white 

 injection, and subsequently the arteries with 

 red or yellow. A portion of the small 

 intestine, exhibiting the general capillaries, 

 with the plexuses of the villi, forms a 

 beautiful object as prepared from the rabbit, 

 the rat, <fcc. Among other preparations 

 may be mentioned: the liver of various 

 animals, as the cat, the rabbit, &c. ; the 

 lungs of the cat, rabbit, &c. r in which the 

 capillaries are very minute ; those also of 

 reptiles, as the frog, triton, boa, and other 

 snakes, in which they are coarser, but very 

 beautifully arranged; the lungs of birds'; 

 the kidneys of the frog and triton ; the web 

 of the frog's foot ; the ciliary processes and 

 choroid coat of the eye ; the 'gills of the eel 

 and other fishes ; the lungs of kittens, &c. 

 which have not breathed, the air-cells being 

 injected from the trachea ; the skin of the 

 frog, and especially of the triton, &c. 



BIBL. Tulk and Henfrey, An. Manip. ; 

 Robin, Microscope ; Quekett, on Inject ; 

 Goad by, in Wythes's ' Microscopist-, ' Beale, 

 How fe.j Rutherford, Hist. 1876; Mose- 

 ley, Q. Mic. Jn. 1871, 389, Inject. Insects-, 

 Frey, Mikr. 1881. 



INODER'MA, Kiitz. A genus of Pal- 

 mellaceae (Confervoid Algae). 



Char. Cells oblong, usually in longi- 

 tudinal rows, loosely united by a soft jelly ; 

 thallus gelatinous, membranous, irregularly 

 expanded. 



/. lameUosum. On submersed wood and 

 stones, everywhere. 



BIBL. Rabenhorst, Fl. Alg. iii. p. 37. 



INOME'RIA, Kutz. A genus of Oscil- 

 latoriacese (Confervoid Algae) with calca- 

 reously hardened incrusting fronds, growing 

 on stones in fresh water. Fronds composed 

 of vertical, parallel, whip-shaped filaments, 

 with the sheaths obscure, connected to- 

 gether, and decomposed into very slender 

 fibrils above. Kiitzing supposes his /. Rce- 

 meriana to be synonymous with Hassall's 

 Lithonema crustaceitm. 



BIBL. Kiitz. Sp. Alg. 343, Ic. Phys. ii. pi. 

 83 ; Hassall, Alga, 266, pi. 65. fig. 3 ; Ra- 

 benhorst, Fl. Alg. ii. 223. 



