Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: May 6, 2025
If we let our gaze travel beyond the creatures that are possessed of a glimmer of intellect and consciousness, beyond the protozoa even, which are the first nebulous representatives of the dawning animal kingdom, we find, as has been abundantly proved by the experiments of Mr.
The disease-producing protozoa of this kind are frequently parasitic in the blood of man and animals, and were only recently recognised, after the disease-producing bacteria of many kinds had been thoroughly studied.
The masterly work of Tyndall and Louis Pasteur in doing for the bacteria and protozoa what Redi had done for the larger organisms, is too much a matter of modern contemporary history to need recital here. Upon this great truth of life only from life is based all the recent advances in the treatment and prevention of germ diseases and all the triumphs of modern surgery.
But as far as the transmission of effects of somatic changes is concerned, if protozoa undergo special modifications under the influence of external conditions, will not the germ-cells undergo special modification under the influence of changes in the somatoplasm which forms their immediate environment?
But in spite of their complexity, all the changes of "growing up" are explained and understood by the simple formula that the mode of individual development owes its nature primarily to the hereditary influence of earlier ancestors back to the original animals which were protozoa. Embryology as a distinct division of zoölogy has grown out of studies of classification and comparative anatomy.
There are only two orders extinct among the 'Crustacea'. There is not known to be an extinct order of these creatures, the parasitic and other worms; but there are two, not to say three, absolutely extinct orders of this class, the 'Echinodermata'; out of all the orders of the 'Coelenterata' and 'Protozoa' only one, the Rugose Corals.
The same tendency is met with again at a higher stage, in the protophytes, which, once having quitted the parent cell by way of division, remain united to each other by the gelatinous substance that surrounds them also in those protozoa which begin by mingling their pseudopodia and end by welding themselves together. The "colonial" theory of the genesis of higher organisms is well known.
Of course the division of one being to form two is perfectly familiar in the case of those lowly, single-celled creatures such as the protozoa and the bacteria, but it seems quite another matter when one thinks of cutting a fish in two and having two complete living fish remaining. Yet this is virtually what the biologists did.
The PROTOZOA. The Protozoa are represented throughout the whole range of geological series, from the Lower Silurian formation to the present day.
They had analysed soils, estimated the rainfall, and examined the germination of seeds; they understood such mysterious terms as bacteria, protozoa, cotyledons, trenching and ridging, cross-fertilization and spermatozoids, and had some elementary acquaintance with the theory of the rotation of crops.
Word Of The Day
Others Looking