Pseudopodium

“ Wherever the surface of the body is covered by pseudopodia, those processes, inasmuch as they have a power of spontaneous movement, enable the creatures possessing them slightly to aid or to resist the drifting action of the water in which they float.
But a living organism may be devoid of any definite shape whatever, as in Protamœba, [66] which consists of a mere particle of protoplasm, from which irregular-shaped processes of unequal size are irregularly protruded in every direction, so that the form of the creature may be said to be quite indeterminate. ”

“ Unfortunately, bichromate of potash is not very soluble in water; one pint of water will not take up much more than three [Pg 47] ounces of this salt. Hence, though the solution of potassium bichromate is an excellent depolariser as long as it contains any of the salt, it soon becomes exhausted. When bichromate of potash is used in a cell along with sulphuric acid and water, sulphate of potash and chromic acid are formed, thus:—
From this we learn that before the potassium bichromate enters into action in the battery, it is resolved into chromic acid. ”

“ No recorded observations on the endoplasm along the length of a pseudopod can be arranged so as to form{88} a gradient which would suggest a similar gradient in metabolic rate; and if the endoplasm is a passively moved fluid as Hyman’s theory seems to imply, a metabolic gradient would seem to be precluded.
In the ectoplasm however there exists a time gradient; that at the base of a pseudopod is older than that near the tip, and observation generally tends to confirm the view that the older it is the firmer it becomes. ”

“ The former of these consists, at one stage of its existence, of a small globular mass of protoplasm, from the whole periphery of which a multitude of fine pseudopodia radiate. When about to reproduce, the creature retracts its pseudopodia, and forms around its exterior a structureless coat or cyst, an action which takes place frequently in lowly organisms, and is called their process of encystment. The contents of the cyst then divides into separate bodies, which escape by the rupture of the cyst. ”

“ The Matrix, placed between the calymma and central capsule, in the majority of the Acantharia is a rather thin layer of granular exoplasm.
The Pseudopodia arising from it are not so numerous as in the Spumellaria, and not so equally disposed over the whole surface. Also their tendency to ramify, anastomose, and form networks seems to be much less developed. Commonly they are simple or little ramified. In many cases (and perhaps everywhere) there may be distinguished two different kinds of pseudopodia:— (1) Axopodia, or permanent pseudopodia (with axial filaments?) ”

“ Being a theory, it is the province of the wise man to ridicule it and call it absurd. I will confess that your criticism of it is not clear to me and I still do not see its absurdity. I don’t see what relation your argument, that the phosphates of sodium and potassium do not draw the calcium from the blood, brains and bones, has to the theory I advanced. It is true that I have no private mark by which I can identify the amorphous phosphate produced by amorphous phosphorus, but such argument is puerile. ”

“ Thus, from phosphatides, phosphoric acid is generated, and they could also be called phosphagens. Since 1926, however, the name phosphagens has been reserved for a group of organic substances that release their phosphoric acid very readily. The link between phosphorus and carbon is provided by oxygen in the phosphatides, by nitrogen in the phosphagens. In vertebrates, the basis for the phosphoric acid is creatine, whereas invertebrates have arginine instead.
Creatine Phosphate
Arginine phosphate Nuclein and Nucleic Acids
All parts of an organism are essential for life. ”

“ Phosphates abound in seeds and ova, in muscles and ganglia, and are deficient in the woody parts of plants and the elastic fibres of animals. The infant absorbs phosphates in large quantities and excretes them in small quantities. Nervous activity is accompanied by the consumption of a third more phosphorus than accompanies muscular activity. Phosphates are among the most energetic of organic stimulants. But who would endow the phosphates with Vitality, on the ground of their indispensable presence in all vital processes?
75. Life, as we saw, is the expression of the whole organism. ”

“ The body substance is granular, with a spherical, sharply contoured nucleus and an accessory nuclear body. No vacuoles are present, but occasionally the endoplasm contains red blood corpuscles. The pseudopodia are hyaline, finger- or lobe-shaped, and are protruded either singly or in twos. Multiplication is by binary fission and by the formation of spherical cysts (15 μ to 20 μ in diameter) in which occurs successive division of the nuclei, ultimately forming ten to twelve roundish bodies each of which soon develops a flagellum. ”

“ Another challenge is the use of some terms (such as acropodium) to refer to different structures in different contexts. In some papers “acropodium” only refers to the phalanges (e.g. [29] ) , but in others it refers to the entire manus skeleton excluding the mesopodium (e.g. [30] , [31] ) . In keeping with the definitions created by Haeckel we decided to use ‘acropodium’ (or ‘acropodial skeleton’) for the phalanges and introduce a new term, the ‘digitopodium’, for the metapodium/acropodium complex (Figure 3) . ”

“ The communications between the successive chambers, and between the last chambers and the exterior (whether formed by a single large aperture as in Miliola, or by the multiplication of smaller pores as in Peneroplis,) are very free; having to give passage not merely to stolons which are subservient to the multiplication of segments, but to bands of sarcode-substance large enough to transmit with facility, to the segments that are furthest removed from the exterior, the nutrient materials obtained by the pseudopodia which issue from the last alone. ”

“ It fastens itself to the substrate at the tip. It then contracts, pulling the Difflugia forwards. While this pseudopod is contracting, another one is extended in the same direction. When it has arrived at the maximum length, it fastens itself at the tip and then contracts, pulling the Difflugia along. Continued locomotion consists of a repetition of this process. The pseudopods are slender and consist nearly always of clear protoplasm. Only occasionally does one see conspicuous endoplasmic granules flow into a pseudopod, and then only at the base. ”

“ The pseudopodia are lobose, sometimes absent, the body then progressing by a flowing movement; the body consists of ectoplasm and endoplasm, the latter being granular and internal, the former hyaline and external. There is always one nucleus and one vacuole, but both may be more numerous. Reproduction takes place by division or by spore-formation. ”

“ The report presented evidence to show that the glycero­phosphates are not absorbed as such, but that they are split into inorganic phosphates before absorption. The Council showed that there was convincing evidence that the animal organism synthesizes its complex organic phosphorus constituents from inorganic phosphates, and that organic phosphorus is of no more value as a food than inorganic. Despite this the Neuro Phosphates advertising makes use of the fallacious assumption regarding the action of the glycero­phosphates. ”

“ Salts are formed when a “basis,” i.e., a metal oxide, replaces water. When potassium-acid sulfate is neutralized by sodium base, the acid-salt divides into Glauber’s salt and potassium sulfate, which proves the acid-salt to be a mixture of the neutral salt with its acid. Sodium-acid phosphate behaves quite differently. After neutralization by a potassium “base” (hydroxide) , the salt does not split up; a uniform sodium-potassium phosphate is obtained. Therefore, phosphoric acid is truly three-basic! ”

“ If a still stronger stimulus is applied by firm pressure at the end of the pseudopod the process takes place with much greater violence. The differentiation of the protoplasm spreads centripetally from the point of stimulation over the whole pseudopod with great rapidity, and produces a quick retraction in the same, then involves the oppositely directed pseudopod, in which it then extends more and more slowly, until, proceeding in a centrifugal direction, it is at last gradually completely obliterated. ”

“ The positions of the protoplasm which the vesicles fashion change continually; only the grainless protoplasm of the pseudopodia develops no air. After long and fruitless efforts a manifest fatigue sets in; the animal gives up the attempt for a time, and resumes it after an interval of repose.
Engelmann, the discoverer of these phenomena, says (Pflüger’s Archiv für Physologie, Bd. II.) : “The changes in volume in all the vesicles of the same animal are for the most part synchronous, effected in the same manner, and of like size. There are, however, not a few exceptions ”

“ The phosphorescence of the central capsule, too (§ 223) , may be regarded as a useful protective arrangement; as also the radiating of the numerous pseudopodia in all directions from the surface of the calymma; for they are of great significance to the well-being of the organism, both as sensory organs and as prehensile organs. By far the most important and most varied means for the actual defence of the soft body is to be seen in the endless modifications of the skeleton ”

“ Sometimes dialyzed iron, half to one teaspoonful in water, taken in the middle of the meal, acts best, though I prefer the pyrophosphate, as phosphorus in some form should always be given for some time to these patients; it is to be remembered that the iron, potassium and other elements of the blood cells are united as phosphates. Occasionally I have to give the acetate of potassium with nux vomica and infusion of quassia after meals, in place of the other mixture, which after a while may be distasteful. ”

“ In 1807, Sir Humphry Davy discovered the metal potassium by subjecting moistened potash to the action of a powerful voltaic battery; the positive pole gave off oxygen and the metallic globules of pure potassium appeared at the negative pole. It is never found uncombined in nature. Now if potassium is heated in cyanogen gas (a gas procured by heating mercury) or obtained on a large scale by the decomposition of yellow prussiate of potash, a white crystalline body very soluble in water, and exceedingly poisonous, is obtained. ”

“ At 32° F. it is brittle, like glass; at 59° it is soft and malleable; at 144° it becomes liquid. Potassium is widely diffused in the vegetable, animal and mineral kingdoms. Some of the more important potassium compounds are caustic potash (the hydroxide) , the carbonate, the bicarbonate; also potassium chloride, bromide, iodide, nitrate (saltpeter) , sulphate, chlorate, cyanide etc. Of these iodide, bromide and chlorate are used for medicines, the others being employed more or less in the arts. ”

“ Some dozen years ago it was discovered that in many cases vegetal cells are connected with one another by threads of protoplasm—threads which unite the internal protoplasm of one cell with the internal protoplasms of cells around. It is as though the pseudopodia of imprisoned rhizopods were fused with the pseudopodia of adjacent imprisoned rhizopods. We can not reasonably suppose that the continuous network of protoplasm thus constituted has been produced after the cells have become adult. ”

“ The entire absence of anything like a membranous envelope is evinced by the readiness with which the pseudopodian extensions fuse together whenever they come into contact, and with which the principal branches subdivide into finer and yet finer threads, by whose continual inosculations a network is produced that might be almost described as an animated spider's web. Any small alimentary particles that may come into contact with the glutinous surface of the pseudopodia are retained in adhesion by it, and speedily partake of the general movement going on in their substance. ”

“ Only four individuals are visible, the central capsule of which contains numerous small nuclei and a central oil-globule. The including spherical lattice-shell is provided with a few (one to four) larger apertures, which are prolonged into short cylindrical tubules. Through these latter radiate bundles of fine pseudopodia, branching and anastomosing, and forming a fine sarcode network between the alveoles of the calymma. On the surface of the alveolated jelly-sphere the pseudopodia form a dense radiating zone. Xanthella or yellow cells are everywhere scattered. ”

“ Its form is not constant during activity, for fingerlike processes called pseudopodia are pushed out tentatively in many directions to be followed as circumstances direct by the materials of the whole cell body. Other protozoa differ in possessing constant forms, or in having constant vibratile processes, or shells of some kind, while in still other cases like individuals combine to make colonies which are more or less definite and permanent. Here at the very foot of the organic scale are found animals which seem to be entirely different from those above. ”

“ The general trait which here concerns us, is that while its plastic or semi-fluid sarcode goes on protruding, in irregular ways, now this and now that part of its periphery, and again withdrawing into its interior first one and then another of these temporary processes, perhaps with some small portion of food attached, there is but an indistinct differentiation of outer from inner (a fact shown by the frequent coalescence of the pseudopodia in Rhizopods) ”