288 



SCIENCE-GOSSIP. 



Plastin is insoluble in water, in ten per cent, salt 

 solution and in ten per cent, solution of sulphate of 

 magnesia ; it is precipitated by weak acetic acid, 

 while concentrated acetic acid causes it to swell up. 

 It resists both pepsin and trypsin digestion ; it is 

 hardly or not at all stained by baser aniline dyes, 

 but it is stained with acid ones, such as eosin, 

 etc. ( 4 ). 



Living protoplasm is distinctly alkaline, and 

 moreover the metabolic products demonstrated in 

 protoplasm are most different ; they are attributed 

 either to metamorphic progression or retrogression, 

 and as an illustration of the similarity of the 

 constitution of animal and vegetable cells, the 

 following substances are common to both — pepsin, 

 diastase, myosin, sarcin, glycogin, sugar, inosit, 

 dextrin, cholesterin, and lecithin, fat, lactic acid, 

 formic acid, acetic acid, butyric acid, etc. Kossel 

 quotes in his text book the quantitative analysis 

 of ( 5 ) a cell as made by Hoppe Seyler, the substance 

 being pus corpuscles. One hundred parts of the 

 substance, by weight, being taken, gave the 

 following results : 



Various albuminous substances - 13762 

 Nuclein - 34' 2 57 



Insoluble substances - - - 20-566 

 Cholesterin ----- 7400 



Cerebrin 5' IC ;9 



Extractives ----- 4*433 

 The ash yields the following substances — 

 phosphorus, sodium, iron, magnesium, calcium, 

 phosphoric acid and chlorine. 



As I have previously urged, the discovery of 

 animal protoplasm was induced by the investigation 

 of the constituents of the vegetable cell, the nuclei, 

 large coloured granules, etc., becoming objects 

 of investigation by those interested in the fruits of 

 scientific discovery. Protoplasm being recognised 

 as the base matter or matrix from which the animal 

 and vegetable bodies are built, naturally excited 

 attention, more especially as to the functional 

 action of the nuclei, etc., and so introduced the 

 apparently structureless mass of homogeneous 

 matter into the field of speculative theory. When 

 the action of the nuclear and granular bodies was 

 being worked out, the affinity between these and 

 the structureless mass suggested itself, with the 

 result that the mass was found, in place of being 

 structureless as had hitherto been the idea, to be 

 possessed of a very well-defined formation, which 

 originated several theories. 



This matter was originally regarded as consist- 

 ing of a viscid mass of a more or less homogeneous 

 nature with granules, i.e. microsomata, embedded 

 therein ; the viscid mass, being more or less con- 



(«)"The cell," O. Hertwig. Translated by Campbell. 

 London, 1895. Swan, Sonnenschein and Co. p. 17. 



( 5 ) Schieferdecker u. Kossel. " Gewebelehre mit besondere 

 Betiicksichtigung des nienschl. Kbipers." 



tractile, enabled the granules to move about, so 

 that often arranging themselves in rows, they 

 caused the substance to assume a fibrillar appear- 

 ance. This led others, and amongst them 

 Flemming ( G ), to regard the matrix as not being 

 of a homogeneous nature, but divided up by fine 

 contractile fibrillae, between which, or within 

 which — it was not definitely stated— the granules 

 assumed their place. The fibrillae vary in length, 

 being in some cells longer than in others, but 

 what their chemical composition was Flemming did 

 not enlarge on. Kunstler was induced, from the 

 examination he made of the flagellate protozoa, to 

 consider protoplasm to be more or less vacuoleated 

 in structure, on account of the existence of what he 

 regarded as small vesicles ; but further researches 

 resulted in the generally accepted theory that 

 protoplasm was not a homogeneous matrix formed 

 of an accumulation of vesicles, but was possessed 

 of a structure in appearance like network. These 

 trabecular consist of a colourless hyaline, within 

 which are embedded the darker granules or micro- 

 somata. The meshes, however, form only a sponge- 

 like framework, the interstices being filled in with a 

 liquid or viscid sap, the chynema ( 7 ). Strasburger( fl ), 

 an eminent observer and careful naturalist, and one 

 of the most able exponents of the reticular theory, 

 adopted this view. This definition of protoplasm 

 did not, however, fully account for the peculiar 

 activity which the substance was endowed with, 

 and it occurred to Butschli, who had been investi- 

 gating the structure of protoplasm, that to arrive 

 at a correct and comprehensive idea of the structure 

 of the substance, it must be from the physical and 

 morphological conditions of life that any attempts 

 to investigate its properties must be under- 

 taken. With this end in view he was, after 

 several experiments, able to produce eventually a 

 substance which to his mind fully exhibited the 

 appearance of protoplasm when viewed under the 

 microscope, and which was apparently endowed 

 with some of the characteristic mechanical move- 

 ments of living protoplasm, the substance assuming 

 for considerable periods of time — even days — the 

 amoeboid movement of naked masses of the 

 substance. This experiment caused Butschli to 

 conclude that the phenomenon of movement 

 exhibited in protoplasmic masses could not be 

 attributed to the voluntary action of the living 

 protoplasm, but resulted from the physical structure 

 of the substance, which structure he considers to 

 be made up of a mass of small vesicles ( s ). 



(°) Flemming. " Zellsubstanz, Kern und Zelltheilung." 

 Leipzig, 1882. 



(?) Manchester Microscopical Society's Transactions, 1893. 

 " The Structure of Protoplasm." Weiss. 



( s ) "Studienilber das Protoplasrna." Jenaische Zeitschrift, 

 1876. Bd., x. 



( 9 ) Butschli. "Ueber die Structur des protoplasmas ver- 

 handlungen des Naturlaist-Med-Vereins zu Heidelberg." 

 N., F., Bd., iv., Heft. 3, 1889. Heft. 14, 1896. See " Quarterly 

 Journal Microscopical Society," 1890. 



