The presence, however, of apparatus or observers upsets the conditions, while above uneven ground or near a tree or a building the equipotential surfaces cease to be horizontal.
Cells treated by reagents, has been interpreted by many observers as a network of threads embedded in a homogeneous ground-substance.
In Spirogyra the pyrenoids are distinctly connected by cytoplasmic strands to the central mass of cytoplasm, which surrounds the nucleus, and according to some observers, they increase exclusively by division, followed by a splitting of the cytoplasmic strands.
Many observers hold the view that the chromosomes are pulled apart by the contraction of the fibres to which they are attached.
Rosenberg (1909) adduces evidence fox the existence of chromosomes or prochromosomes in resting nuclei in a large number of plants, but most observers consider that the chromosomes during the resting stage become completely resolved into a nuclear network in which no trace of the original chromosomes can be seen.
The central body probably plays the part of a nucleus and some observers consider that it has the characters of a typical nucleus with mitotic division.
Some observers consider that the yeast nucleus possesses a typical nuclear structure, and exhibits division by mitosis, but the evidence for this is not very satisfactory.
From time to time there have been observers who have maintained a belief in the opposite theory, to which the name heterogenesis has been given.
To the first belong what may be called the physical phenomena (q.v.) of spiritualism - those, namely, which, if correctly observed and due neither to conscious or unconscious trickery nor to hallucination or illusion on the part of the observers, exhibit a force acting in the physical world hitherto unknown to science.
Probably most persons who have studied the subject would now be inclined to go this length; and there is some evidence, notably in connexion with the trances of an American medium, Mrs Piper,' which has convinced some good observers that the hypothesis of occasional communication from deceased persons must be seriously entertained.
The strange contrast between the succession of dynasties and kings cut off by assassination in the northern kingdom, ending in the tragic overthrow of 721 B.C., and the persistent succession through three centuries of the seed of David on the throne of Jerusalem, as well as the marvellous escape of Jerusalem in 701 B.C. from the fate of Samaria, must have invested the seed of David in the eyes of all thoughtful observers with a mysterious and divine significance.
From the time of Hippocrates onwards the malarial or periodical fevers have engaged the attention of innumerable observers, who have suggested various theories of causation, and have sometimes anticipated - vaguely, indeed, but with surprising accuracy - the results of modern research; but the true nature of the disease remained in doubt until the closing years of the 19th century.
Quartan and malignant types of fever, have been described by Italian observers, and the classification is generally accepted;.
Thus we get a complete scientific demonstration of the causation of malaria in three stages: (1) the discovery of the parasite by Laveran; (2) its life-history in the human host and connexion with the fever demonstrated by the Italian observers; (3) its life-history in the alternate host, and the identification of the latter with a particular species of mosquito by Ross and Manson.
Some observers maintain that Anopheles does not "sing," like the common mosquito, and its bite is much less irritating.
In the other animals several parasites have been described by different observers, but the alternate hosts are not known.
C. McCook in the American genus Myrmecocystus, and by later observers in Australian and African species of Plagiolepis and allied genera.
In all probability the actions of ants are for the most part instinctive or reflex, and some observers, such as A.
England's commercial relations with Charles V.'s subjects in the Netherlands put war with the emperor almost out of the question; and cool observers thought that England's obvious policy was to stand by while the two rivals enfeebled each other, and then make her own profit out of their weakness.
At low tide the limpet (being a strictly intertidal organism) is exposed to the air, and (according to trustworthy observers) quits its attachment and walks away in search of food (minute encrusting algae), and then once more returns to the identical spot, not an inch in diameter, which belongs, as it were, to it.
Wagner made his classical observations on the production of larvae from unfertilized eggs developed in the precociouslyformed ovaries of a larval gall-midge (Cecidomyid), and subsequent observers have confirmed his results by studies on insects of the same family and of the related Chironomidae.
The work of de Reaumur and de Geer on the bionomics and life-history of insects has been continued by numerous observers, among whom may be especially mentioned in France J.
16-18, be not over-righteous (over-attentive to details of ritual and convention) or over-wicked (flagrantly neglectful of established beliefs and customs); here "righteous" and "wicked" appear to be technical terms designating two parties in the Jewish world of the 2nd and 1st centuries B.C., the observers and the non-observers of the Jewish ritual law; these parties represent in a general way the Pharisees and the Sadducees; viii.
Stromeyer detected a new metallic element, cadmium, in certain zinc ores; it was rediscovered at subsequent dates by other observers and its chemical resemblance to zinc noticed.
Physico-chemical properties have also been drawn upon to decide whether double unions are present in the benzene complex; but here the predilections of the observers apparently influence the nature of the conclusions to be drawn from such data.
The first was that people who got it and survived never got it again; that had been noted centuries before by the Persian physician and by numerous observers since.