Sphygmograph

“ It may be expected that the analysis of the conditions of the experiment will give an insight into the origin of the sphygmographic curves, because the tracings which Grashey and Marey took from the walls of a rubber tube resemble closely the tracings of the human pulse. This experiment, first, proves that the form of the curve depends merely on physical conditions. The movement of a point of the wall of the tube depends on the following four factors: (1) The elasticity of the wall ”

“ It is true that the finger can detect some difference in pulse tension, but it is often entirely at fault, since it can only estimate total pressure, thus missing a high pressure, if the volume be small. In the same way, although the hand can detect differences of temperature, it cannot replace the thermometer. The sphygmomanometer has enlarged our ideas, cleared up difficulties in diagnosis, and helped in prognosis. ”

“ This smooth hammerhead, Sphyrna zygaena (SIO 64-528; SL 104 mm) was imaged at 3T with the following 3D FSPGR pulse sequence parameters: FA = 35°, TR = 9.86 ms, TE = 4.11 ms, slice thickness = 900 μm, slice matrix = 512×512×236, resolution = 683 μm3, averages = 2. It was scanned in 4 sections and pieced together in Amira for segmentation. A selection of segmented soft tissue structures are color-coded as follows: brown = alimentary tract; dark blue = eyes; green = olfactory system; light blue = brain; magenta = dorsal aorta; puce = liver; red = heart; white = spinal cord. ”

“ The texture of this Touch-wood seems more like that of a Lock or a Fleece of Wool, for it consists of an infinite number of small filaments, all of them, as farr as I could perceive, of the same bigness like those of a Sponge, but that the filaments of this were not a twentieth part of the bigness of those of a Sponge; and I could not so plainly perceive their joints, or their manner of interweaving, though, as farr as I was able to discern with that Microscope I had, I suppose it to have some kind of resemblance, but the joints are nothing neer so thick, nor without much trouble visible. ”

“ The capsule (fig. 5) is roundish-ovate, without a peristome, and the operculum is flattened. The grouped arrangement of the upper branches renders the species of Sphagnum easily recognized. The structure of the leaves is also very peculiar and characteristic (fig. 2) . The cells of which they consist are of two kinds, one (fig. 2 a) being colourless, elongate, pointed, and containing a spiral fibre; the other consisting of shorter and narrower obtuse cells, containing chlorophyll, and situated between the former. ”

“ The Ephyra differs from the adult in many respects. The disc is thin and flat, the manubrium short, the margin of the umbrella deeply grooved, while the statorhabs are mounted on bifid lobes which project outwards from the margin. The stabilisation of the Scyphistoma is a process of reproduction by transverse fission, and in some cases this is supplemented by gemmation, the Scyphistoma giving rise to a number of buds which become detached from the parent and subsequently undergo the process of strobilisation. ”

“ Spores: medium sized, oblong, hyaline under the microscope, not blueing in solutions containing iodine and 6-7 × 2-5 μm in size.
Facial and marginal cystidia: absent.
Habitat & Distribution: Grows on fallen branches, trunks, dead wood, etc.
General Information: Easily recognised by the ‘gills’ radiating from a point and becoming ‘split’ when dry. Specimens of Schizophyllum sealed by A. H. R. Buller in a tube in 1911 have been shown on remoistening to unroll their gills and shed variable spores, after 521⁄2 years—probably a world record! ”

“ A great proportion of the perfect insects have hyaline spots and patches in their wings, and nearly all of them are brilliantly coloured. It is known that Linnæus occasionally, as in Tenebrio and the present instance, made his genera recipients of species, which he found a difficulty in locating properly; but it is really astonishing to find a naturalist like Latreille abiding by so absurd a combination as the contents of the Linnæan genus Sphinx, and, in servile imitation, calling creatures which nothing but an unclouded sun ever tempts abroad—Crepuscularia. ”

“ The tube is arranged like the draw tube of a microscope. It is made long, so as to admit of taking small hearts at life-size. The stand carries a support for the frog or other animal to be experimented upon, and a bottle of physiological salt solution kept warm by a spirit lamp beneath.
FIG. 2.—INTERIOR OF THE CAMERA.
The whole apparatus is readily packed in a small space. I have already taken a number of photographs of various hearts and intestines with it, and the contraction of the heart of the frog produced by Strophanthus hispidus, the new cardiac stimulant, is seen in Fig. ”

“ I refer to the coloured edges of the oblique stripes which occur in most of the species of the genus Sphinx. It has already been insisted upon in a previous section, that the mode in which this character originates negatives the assumption of a phyletic force, because these coloured edges are gradually built up out of irregularly scattered spots. There is no occasion for a “developmental force” to grope in the dark; if such a power exists, we should expect that it would add new characters to old ones with the precision of a master workman. ”

“ To show the finer dots clearly, a valve should be crushed, so as to obtain a fragment as flat as possible; for the surface of the valves is curved more or less in all the species. The valves of G. angulatum are generally used to test the quality of the object-glasses of the microscope, and also for practice in “making out” the lines and dots; there are, however, many Diatomaceæ more difficult. ”

“ Whoever will give himself the trouble to examine thoroughly a collection of British Lepidoptera, will find a very great majority of them evincing very evident symptoms of relation to one or other of the following species:—Papilio Machaon, Sphinx Ligustri, Pyralis verticalis, Tinea pellionella, Noctua pronuba, and Geometra roboraria; and should any form widely different from either of these occur, it may, if the larva be known, be placed in the centre of a ring formed by the groups, which we will suppose surrounding their six respective types ”

“ The sun was already high in the heavens, and no shadow Sphinx rested on the green turf. Ann had not expected to find it; she understood now why the artist had worked on the picture in the afternoon instead of in the morning. She knelt in front of the Sphinx picture and examined it critically, noting each detail of the curious figure, and tracing the ribbon-like band to the edge of the stone. Here she came upon the tiny arrows pointing outward. Surely, since the picture was an exact copy of the shadow and brook, with the exception of these arrows, might not they mean something of importance? ”

“ Under the compressorium the thread suddenly cracks, with a start and a crepitation distinctly audible; a curious circumstance, which seems to indicate a crustaceous or siliceous structure somewhere. I think it cannot be the walls of the filament itself, but the capsules, that crack, minute as they are. The filament is more densely filled with capsules than that of any species which I am acquainted with: perhaps there are even millions of them. The capsules are of about the average size of those found in other Actiniæ; viz. ”

“ Fig. 4 is a single elater much magnified, showing it to be a spirally coiled filament, that, by sudden expansion, shoots out the spores just as a child’s toy-gun discharges the arrow. Fig. 5 is a part of the leaf of the Sphagnum moss, common in fresh water, showing the curious spiral arrangement of secondary fibre which is found in the cells, as well as the circular pores which are found in each cell at a certain stage of growth. Just below, and to the left hand, is a single cell greatly magnified, in order to show these peculiarities more strongly. ”

“ Since his day it is a well-known experience of those who take up the microscope that the most interesting objects to commence with are infusorial living creatures of sufficient dimensions to be easily understood and seen with moderate magnifying powers. Moreover, infusoria are more readily found in almost any pool or running stream of water, either near the surface or clinging to the under surfaces of aquatic plants. ”

“ They might have many worse friends. But a better one still is the Sympalmograph or Harmonograph, especially the old-fashioned kind, made of two pendulums swinging different ways, and holding between them a pen, which traces exquisite curves that suggest wings, and flames, and strange unknown flower-forms. ”

“ Here we are with the apparatus ready. We have [12] transferred a few threads of the conferva from the bottle to the live box, spreading out the fine fibres with a needle, and adding a drop of water. The cover is then gently pressed down, and the whole placed on the stage of the microscope, to be examined with a power of about sixty. A light is thrown somewhat obliquely by the mirror through the object, the focus adjusted, and a beautiful sight rewards the pains. Our mass of conferva turns out to contain one of the most elegant species. ”

“ Turrited, fusiform, thick, smooth or ribbed; aperture oval, terminating anteriorly in a long canal, posteriorly in a channel running up the spire; outer lip dilated, thickened, sometimes digitated, running up all or part of the spire, with a sinus near the anterior canal; inner lip smooth, spread over part of the body whorl and of the spire. The Red Sea and the Indian Ocean produce the few known species of this genus.—Obs. Hippochrenes is the name given by De Montfort, to those fossil species which have the outer lip simple and very much dilated. R. curvirostrum, fig. ”

“ That so simple and minute an organism should be capable of independent motion is indeed surprising. Dujardin, a French physiologist, termed this animated matter sarcode. On a closer study of the numerous forms of animal life it was found that all were alike composed of this sarcode substance, some apparently not having a cell wall. The same seemed to hold good of certain higher forms of cells, the colourless blood corpuscles for instance, which under high powers of the microscope are seen to change their shape, moving about by the streaming out of this sarcode. ”

“ For there, outlined on the dark green earth, was a gigantic Sphinx, made by the shadows of an irregular cluster of trees and bushes; more than that, Silver Brook emerged from the shadow at the top of the great head, ran downward jon the east side, doubled on itself, wavered across the field, and was lost to view in the northeast corner, which corresponded exactly to the upper right-hand corner of the stone. Ann compared the shadow Sphinx with the stone one, giving way to little bursts of joy as the points of interest proved similar to one another. ”

“ The leaves, which are only employed in a fresh state, are 6 to 10 inches in length, with long stalks, ovate, often unequal at the base, acuminate, coarsely dentate with a few spreading teeth. They evolve an offensive odour when handled.
Microscopic Structure—The testa is built up of the same tissues as in D. Stramonium, but the thick-walled cells constituting the spongy part are far larger, and distinctly show numerous secondary deposits, making a fine object for the microscope. ”

“ Those most frequently met with, and which attract the most attention from observers, are furnished with vibratile cilia, which cover the whole body, acting as paddles. These organs are evidently intended to propel the animal from one place to another. At other times they appear to be employed in conveying food to the mouth, if we may use the expression. Some Infusoria are without these cilia, having only one or many very slender filaments, the undulating movement of which suffices to determine their progression through the liquid which surrounds them. ”

“ CREUSIA. Leach. (Creux, se. Fr. a cavity.) Fam. Balanidea, Bl. Order, Sessile Cirripedes, Lam.—Descr. A depressed cone, consisting of four valves, supported upon, and jointed to, a cup-shaped cavity formed in the Madrepores, in which it resides. Aperture quadrilateral, closed by an operculum of four valves.—Obs. This genus is distinguished from Pyrgoma, which is supported on the edge of a similar cup-shaped cavity, by the paries being composed of four valves, whereas in Pyrgoma, it consists of a single piece. Fig. ”

“ The tail is brush-like, and when it swept over the door or valve that leads into the bladder, I saw that the door would immediately fly open and always draw the larva in. I soon became satisfied that the valve was very sensitive when touched at the right point, but to this day I cannot tell what the [69] power is that so quickly draws the creatures within. I earnestly hope that some young microscopists will yet be able to ferret out the cause of this singular power. ”

“ Coursing through its body is seen a system of vessels, beginning as large tubes, which, getting smaller, are finally lost as twigs. This system of vessels is supposed to be the same as that observed in an undeveloped condition in the Paramoecium among the Infusoria, and is found also in the Rotatoria, one of the divisions of the Articulated Worms.
The Articulated Worms include the three groups of the Gephyrea, Annelida, and Rotatoria, They are called articulated or segmented, from the fact of their bodies being composed of segments or pieces joined together. ”