The organism is an actively motile spiral thread, about four times the diameter of a red corpuscle in length.
A few large non-motile bacilli are frequently seen; they cannot be called Boas-Oppler bacilli unless they are numerous and show something of the typical arrangement.
Spirochaete pallida is an extremely slender, spiral, motile thread, with pointed ends.
Illustration: Percent of motile sperm before and after freezing consecutive ejaculates collected within a 4-hour period from each of 6 bulls (Fig.
From the data in Table 3, it is obvious that motilesperm were present after freezing and thawing epididymal samples.
The mean percentages of motile sperm found after thawing thirteen diluted semen samples treated in this manner are shown in Figure 6.
The average percentages of motile sperm found after freezing 10 semen samples at each of the citrate and yolk levels in this experiment are shown also in Fig.
The percentage of motile sperm remained fairly high in the portions that were diluted to 15 million sperm and stored at 5 deg.
The percentage of motile sperm found after freezing and thawing followed the same trend at an average level 10 to 15 percent lower than the prefreezing level.
When the rate of sperm motility following freezing and thawing was considered along with the percent of motile sperm, a slight advantage was found with 16 percent yolk and a citrate concentration of 1.
Illustration: Percent of motile sperm after freezing and thawing semen in diluents containing various levels of egg yolk and various percentages of sodium citrate (Fig.
The percentage of motile sperm decreased slightly at the higher levels of glycerol.
The percentages of motile sperm present after storage at -79 deg.
The mean prefreezing and post-thawing percentages of motile sperm in first and second ejaculates are presented in Table 1.
The mean percentages of motile sperm found before and after freezing and thawing are shown also.
The sperm-cells are motile and swim about in the cavities and canals of the sponge-body until they find egg-cells, which they fertilize.
These represent modified pseudopodia, and in the formation of the motile gametes of some of the lower forms, e.
Atkinson is pretty certain that he has isolated a very motile bacterium in the snow.
He proceeded to draw divisions between the bottom organisms without power of motion, benthon, the nekton motile life in mid-water, and the plankton or floating life.
The motionless form of the anthrax bacillus is of especial value in distinguishing it from the motilebacteria of putrefaction (saprophytes).
In Synura and Chromulina the cells form a spherical motile colony, recalling Volvocaceae.
Fertilization by means of non-motile spermatia and a trichogyne are known among the Fungi in the families Collemaceae any Laboulbeniaceae.
The Cryptomonadeae and Chromulineae are motile through the greater part of their life.
Note the time: Examine the control to determine that the bacilli aremotile and uniformly scattered over the field--not collected into masses.
In the case of non-motile or sluggishly motile organisms, endeavour to measure several individuals in each hanging drop by means of the eyepiece micrometer or the eikonometer (vide page 63), and average the results.
No organism, therefore, should be recorded as non-motile from one observation only; a series of observations at different ages and under varying conditions should form the basis of an opinion as to the absence of true locomotion.
On the other hand, all of the sperm-cells develop into complete active forms, which, as aforesaid, usually become very much elongated and develop a motile organ of some kind.
The motile forms are produced in much greater numbers than the eggs, plainly because they have to seek the egg and many will doubtless perish before this can be accomplished.
Motile zoospores which escape from the zoosporangium are present except in Aplanes.
The formation of the motile spores in the central capsule was first observed by J.
These older observations were, however, incomplete, for the origin of the motile corpuscles from the contents of the central capsule was not observed.
Other species may be motile at one time and stationary at another, while at a third period it is a simple mass of spherical spores.
The cuticle varies considerably in thickness, being well developed in active, intestinal forms, but very thin and delicate in non-motile coelomic forms (e.
In the case of highly-differentiated gametes (Pterocephalus), the actively motile microgametes rush about here and there, and seek out the female elements.
Defn: A small motile spore furnished with two vibratile cilia, found in certain green algæ.
Defn: Having powers of self-motion, though unconscious; as, themotile spores of certain seaweeds.
Defn: A motile condition in plants resulting from exposure to light.
Defn: A genus of motile bacteria characterized by short, slightly sinuous filaments and an undulatory motion; also, an individual of this genus.
Defn: A genus of common motile microörganisms (Spirobacteria) having the form of spiral-shaped filaments.
While many forms are fixed to the substratum, others are free, being in this condition either motile or immotile.
Nor must we overlook the possibility that the endospore-formation in non-motile bacteria more than merely resembles the development of azygospores in the Conjugatae, and some Ulothricaceae, if reduced in size, would resemble them.
In ordinary arable soil there exist motile rod-like bacteria, Bacterium radicicola.
Independent movement is effected by special motile organs, the cilia or flagella.
The monotrichous and lophotrichous conditions are by no means constant even in the motile stage; thus Pseudomonas rosea (Mig.
A motile rodlet with one cilium and with a spore formed inside.
By this is meant the aggregation into clumps of the bacteria uniformly distributed in an indifferent fluid; if the bacterium is motile its movement is arrested during the process.
Piccard did that both the tip and the curving region are sensitive to gravity, but with the important addition that the sensitiveness of the tip is much greater than that of the motile region.
If the motileregion is directly sensitive to gravity the root ought to curve downwards, but this did not occur: on the contrary it continued to grow horizontally.
Pfeffer and Czapek showed that it is possible to bend the root of a lupine so that, for instance, the supposed sense-organ at the tip is vertical while the motile region is horizontal.
By observing whether the root bends up or down we can decide whether the impulse to bend originates in the tip or in the motile region.
After the egg-cells have been fertilized by the non-motile male cells they grow into tubular proembryos, producing terminal embryos.
One of the most important discoveries made during the latter part of the 19th century was that by Ikeno, a Japanese botanist, who first demonstrated the existence of motile male cells in the genus Cycas.
Microspore spherical or oval, with or without a bladder-like extension of the exine, containing a prothallus of two or more cells, one of which produces two non-motile or motile male cells.
The latter ultimately divides in the apex of the pollen-tube into two non-motile generative cells.
Zygote in themotile stage (vermicule or ookinete).
None of the females trapped with males in October was found to be inseminated, and it seems doubtful whether copulation ever occurs at that time of year, although males have motile sperm and seem to be in breeding condition then.
Males were likewise tested for sexual maturity by pipetting a small amount of fluid from the cloaca into a vial and returning it to the laboratory where it was examined microscopically for motile sperm.
They had motile stems, leaves and flowers, and they had cannibalistic tendencies.
There was no grass, because the plants prevented it, but now the motile plants themselves were dead.
A genus of ground-cover plants withmotile stems and leaves and cannibalistic tendencies was considered strong evidence of common origin.
The motile force is imparted to the gonidium by dense rows of waving cilia with which it is completely surrounded.
The upper part of the antheridium becomes separated from the parent stem by a septum, and its contents are converted into ciliated motile antherozoids.
It is a non-motile and a facultative anaërobe; but the presence of oxygen is necessary for a bright colour.
The motile cells, stained by Löffler's method, are seen to have a flagellum in the form of a spiral.
Thus is obtained a view of the organisms in a freely moving condition, if they happen to be motile bacteria.
These cilia, or hairy processes, project from the sides or from the ends of the rod, and are freely motile and elastic.
This is an actively motile rod, the presence of which does not materially affect the milk, but causes the milk products to be of poor quality.
It is motileand possesses flagella, but has no threads.
There is no motile pulvinus in ordinary leaves, and stimulation of the petiole gives rise to no direct or transmittedmotile reaction; from this we are apt to draw the inference that the petiole of ordinary leaves are devoid of perception.
Hence there may be a misgiving that the stimulation of the non-motile side may not induce the effect of indirect stimulus (an increase of turgor and expansion) at the opposite side, which is to inhibit the response.
It was the fortunate circumstance of the insertion of the motile leaf on one side of the Mimosa stem that enabled us to demonstrate the important facts given above.
The responsive movement of motile pulvinus under diffuse stimulus is determined by the greater contraction of the more excitable half of the organ.
A motile organ, including both the pulvinated and growing, will exhibit no geotropic effect on account of the depression of the power of perception through seasonal or other changes, or in the entire absence of the perceptive organ.
Here also stimulation of a non-motile organ at any point, induces at a diametrically opposite point, a positive electric variation indicative of enhanced turgor.
A narrow beam from a small arc lamp was made to fall on the stem, at a point diametrically opposite to the motile leaf, which was to serve as a indicator for induced variation of turgor at the distal side.
The fortunate circumstance of the presence of a motile pulvinus in the neighbourhood enables us to recognise the perceptive power of the petiole, since it transmits an impulse which causes the fall of the leaf.
In the present case the excitatory impulse reached the motile organ 200 seconds after the initiation of the positive response.
When light acts from above the upper half of the pulvinus undergoes contraction, resulting in erection of the motile leaf or leaflets.
By employing the electric method of investigation, I have obtained with ordinary tissues the positive, the diphasic, and the negative electric response, in correspondence with the responses given by a motile organ (p.
In other cells, either of the same filament or else of the small male plants already mentioned, small motile cells, called spermatozoids, are formed.
They are provided with two cilia, closely resembling the motile cells of the Protococcaceæ and Volvocineæ.
