Life-history sentence example
Take this piece of your life history and create a memoir, a glimpse at your life history.
Sharp to indicate a stage in the life-history of an insect between two successive castings of the cuticle.
The vegetable-feeders attack leaves, herbaceous or woody stems and roots; frequently different parts of a plant are attacked in the two active stages of the life-history; the cockchafers, for example, eating leaves, and their grubs gnawing roots.
Macleay's classification (1825), which rested principally on the characters of the larvae, is almost forgotten nowadays, but it is certain that in any systematic arrangement which claims to be natural the early stages in the life-history must receive due attention.
In the Coleoptera we have to do with an ancient yet dominant order, in which there is hardly a family that does not show specialization in some point of structure or life-history.Advertisement
The most interesting of the Heteromera, and perhaps of all the Coleoptera, are some beetles which pass through two or more larval forms in the course of the life-history (hypermetamorphosis).
While from the nature of their life-history there is no doubt that they have a rather close relationship to the Meloidae, their structure is so remarkable that it seems advisable to regard them as at least a distinct tribe of Coleoptera.
Other genera of the family are parasitic on Hemiptera - bugs and frog-hoppers - but nothing is known as to the details of their life-history.
Then, turning his attention to the malaria of birds, he worked out the life-history of these cells within the body of the mosquito.
Birds are subject to malaria, which is caused by blood parasites akin to those in man and having a similar life-history.Advertisement
Gymnosporangium sabinae, one of the rusts (Uredineae) passes one stage of its life-history on living pear leaves, forming large raised spots or patches which are at first yellow but soon become red and are visible on both faces; on the lower face of each patch is a group of cluster-cups or aecidia containing spores which escape when ripe.
This stage in the life-history was formerly regarded as a distinct fungus with the name Roestelia cancellata; it is now known, however, that the spores germinate on young juniper leaves, in which they give rise to this other stage in the plant's history known as Gymnosporangium.
Sharp (1898), the marked divergence among the Hexapoda, as regards life-history, is between insects whose wings develop outside the cuticle (Exopterygota) and those whose wings develop inside the cuticle (Endopterygota), becoming visible only when the casting of the last larval cuticle reveals the pupa.
The presence of the two successive larval forms in the life-history constitutes what is called hypermetamorphosis.
After a prolonged aquatic larval and nymphal life-history, the winged insect appears as a sub-imago, whence, after the casting of a delicate cuticle, the true imago emerges.Advertisement
Occasionally the power of reproduction is thrown still farther back in the life-history, and it is found that from a single egg a large number of embryos may be formed.
The characters of the wings are doubtless important as indications of relationship, but the nature of the jaws and the course of the life-history must be considered of greater value.
The sub-imago of the Ephemeroptera suggests that a moult, after the wings had become functional, was at one time general among the Hexapoda, and that the resting nymph of the Thysanoptera or the pupa of the Endopterygota represents a formerly active stage in the life-history.
The importance of great cardinal features of the life-history as indicative of relationship leads us to consider the Endopterygota as a natural assemblage of orders.
The cotton worm (Aletia argillacea) - also called cotton caterpillar, cotton army worm, cotton-leaf worm - is also one stage in the life-history of a moth.Advertisement
The remarkable life-history of one species, Linguatula taenioides, has been worked out in detail and presents a close analogy to that of some Cestodes.
Only the careful observation of organisms throughout the earlier phases of their life-history can the closely related factors be distinguished with any approach to scientific accuracy.
The exploration of parts of the New World next brought to hand descriptions and specimens of many novel forms of animal life, and in the latter part of the 16th century and the Medical beginning of the 17th that careful study by " special- anatomists" of the structure a.nd life-history of particular groups of animals was commenced, which, directed micro- at first to common and familiar kinds, was gradually scopists.
The perithecia are only produced exceptionally in Europe, but this stage of the life-history is common in the United States and causes a widely spread disease among the American vines.
The complete life-history of this form is at present unknown; and information as to where the fungus passes the winter, and in what form, would probably afford some useful indications as to the method that should be adopted to combat the disease.Advertisement
The life-history of Cestodes consists of larval and adult stages, which are usually passed through in different hosts.
The chief peculiarities that distinguish Trematodes from their free-living allies, the Turbellaria, are the development of adhering organs for attachment to the tissues of the host; the replacement of the primitively ciliated epidermis by a thick cuticular layer and deeply sunk cells to ensure protection against the solvent action of the host; and (in one large order) a prolonged and peculiar life-history.
The life-history of this order offers many points of interest.
A few special cases of this general description of the life-history may be mentioned.
The life-history of Schistostomum haematobium is still unknown, but the difficulty in obtaining developmental stages in any of the numerous intermediate hosts that have been tried suggests that the ciliated larvae may develop directly in man and either gain access to him by the use of impure water for drinking or may perforate his skin when bathing.
The practical importance of this peculiar life-history is very great, since larvae thus protected cannot easily be destroyed.
His researches in the life-history of various of the lower forms of animal life were in opposition to the doctrine that they could be "produced spontaneously, or bred from corruption."
In response to the exceeding diversity of habitat and of the conditions of life, the parasites exhibit manifold and widely-different types of form, organization and life-history.
Among the brachiopods the chief expansion of each type is at a relatively early period in their life-history.
Not only has the number of known forms been greatly multiplied, but the study of the biology and life-history of the parasites has been attended in some cases with remarkable and unexpected results.
That one and the same species may appear entirely different in different phases of the life-history is manifest on comparing, for instance, the chief " forms " of Trypanosoma FIG.
Comprehensive researches (1905, seq.) have made it evident that Trypanosomes have a much more varied and complex development and life-history than was previously supposed.
In other words, he considers that these two Haemosporidian forms are really only phases in the life-history of particular Trypanosomes.
Brumpt (5a), Leger (32, 33), Keysselitz (16), Prowazek (47), Minchin (41b) and others - has undoubtedly shown that much of Schaudinn's scheme of the life-history of a Trypanosome is well-founded.
But detailed study of these various groups of insects shows that beneath their common superficial resemblances lie important distinctions in structure, and essential differences in the course of the life-history.
The insects retained in the order Neuroptera as restricted by modern systematists are distinguished from the preceding orders by the presence of a resting pupal stage in the life-history, so that a " complete metamorphosis " is undergone.
Life-history in some cases very complex and with well-marked sexual process and alternation of generations, in others much reduced; basidium (promycelium) derived usually from a thick-walled spore (teleutospore).
Life-history always very simple, no wellmarked alternation of generations; basidium borne directly on the mycelium.
The matter is complicated by the apogamous transition from gametophyte to sporophyte in the absence of the ascogonium; also by the fact that there are normally two fusions in the life-history as mentioned earlier.
The exact life-history of the truffle is not known.
The Basidiales are further characterized by the complete loss of normal sexuality, but at some time or other in the life-history there takes place an association of two nuclei in a cell; the two nuclei are derived from separate cells or possibly in some cases are sister nuclei of the same cell.
They are distinguished from the other fungi and the rest of the Basidiales by the great variety of the spores and the great elaboration of the life-history to be found in many cases.
We have thus a series showing a progressive reduction in the complexity of the life-history, the lepto and micro forms having a life-history like that of the Basidiomycetes.
This group is characterized by its greatly reduced life-history as compared with that of the eu forms among the Uredineae.
All the forms have the same life-history as the lepto forms of that group, so that there is no longer any trace of sexual organs.
Many fungi, however, cannot complete their life-history apart from the host-plant.
The following table is an adaptation of a scheme devised by Klebs, and indicates the inter-relationships of the marked alternation of generations which of genera- b' dominates the life-history of the higher plants.
Verrill, may also come here, but at present its life-history is unknown.
The greater part of his life-history is preserved in late Biblical narratives, which carry back existing conditions and beliefs to the time of the Exodus, and find a precedent for contemporary hierarchical institutions in the events of that period.
There is a period in the life history of every wine at which it attains its maximum of quality.
To give a connected account of his views is difficult; their full development should be studied in relation with his life-history, the stages of which are curiously parallel to his theory of the progress of man, the fall, the trial, the perfection.
They were then known under the name of " animalculae," and were confounded with all kinds of other small organisms. At that time nothing was known of their life-history, and no one dreamed of their being of importance to man and other living beings, or of their capacity to produce the profound chemical changes with which we are now so familiar.
The supposed constancy of forms in Cohn's species and genera received a shock when Lankester in 1873 pointed out that his Bacterium rubescens (since named Beggiatoa roseo-persicina, Zopf) passes through conditions which would have been described by most observers influenced by the current doctrine as so many separate " species " or even " genera," - that in fact forms known as Bacterium, Hicrococcus, Bacillus, Leptothrix, &c., occur as phases in one life-history.
One of the most remarkable phenomena in the life-history of the Schizomy cetes is the formation of this zoogloea stage, which corresponds to the " palmella " condition of the lower Algae.
Although much progress has been made in determining the value and constancy of morphological characters, we are still in need of a sufficiently comprehensive and easily applied scheme of classification, partly owing to the existence in the literature of imperfectly described forms, the life-history of which is not yet known, or the microscopic characters of which have not been examined with sufficient accuracy and thoroughness.
Their spectra are only imperfectly known in a few cases, and the bearing of the absorption on the life-history is still a mystery.
In the Coelentera the ectoderm and endoderm are set apart from one another at a very early period in the life-history; generally either by delamination or invagination, processes described in the article Embryology.
This was followed by English Men of Science, their Nature and Nurture, published in 1874; Inquiries into Human Faculty and its Development, issued in 1883; Life-History Album (1884); Record of Family Faculties (1884) (tabular forms and directions for entering data, with a preface); and Natural Inheritance (1889).
The parasitic habit is most common among the Copepoda and Isopoda, where it leads to complex modifications of structure and life-history.
The complete life-history, with its regular alternation of gametophyte and sporophyte, is now known in all except a few rare genera of recent Pteridophyta, and will be described in connexion with the several groups.
The rust fungus, Puccinia graminis, is a Uredine belonging to the heteroecious group, that is, one that passes from one host to another at different stages of its life-history.
Not the least interesting features connected with this strange life-history are the facts that the young may be born by the oviparous or viviparous methods and either gamogenetically or agamogenetically, and may develop into winged forms or remain wingless, and that the males only appear in any number at the close of the season.
Its life-history is somewhat similar to that of Aphis rosae summarized above.
One of the most amazing of these stories of total interdependence is the life history of the fig tree and the fig wasp.
For example, some viral genotypes may be particularly prone to transmission or the life history of the host may be important.
Clearly, we need to know more about the life history of the peppered moth.
To the study of the life-history of the butyric and acetic organisms we owe the terms "anaerobic" and "aerobic."
The occurrence in the hypermetamorphic Coleoptera (see supra) of a campodeiform preceding an eruciform stage in the life-history is most suggestive.
While some observers have studied in detail the structure and life-history of a few selected types (insect anatomy and development), others have made a more superficial examination of large series of insects to classify them and determine their relationships (systematic entomology), while others again have investigated the habits and life-relations of insects (insect bionomics).
In their life-history the Homoptera are more specialized than the Heteroptera; the young insect often differs markedly from its After Weed, Riley and Howard, Insect Life, vol.
The Mantispidae are remarkable among the Neuroptera for their elongate prothorax, raptorial fore-legs and hypermetamorphic life-history, the young campodeiform larva becoming transformed into a fat cruciform grub parasitic on young spiders or wasp-larvae (see Mantis-Fly).
If writing your life history results in publication, some of the personal benefits are obvious-potential fame, money, and the feeling that you touched a few lives and inspired (or at least entertained) your readers.
This simple type of life-history has been experimentally proved by Leuckart to be characteristic of Trichocephalus affinis, Oxyuris ambigua and other species.
The Spermatophyta fall into two classes, Gymncsperms (q.v.) and Angiosperms; the former are the more primitive group, appearing earlier in geological time and showing more resemblance in the course of their life-history to the Pteridophyta.
We know very little of the details of reduction in the lower plants, but it probably occurs at some stage in the life history of all plants in which sexual nuclear fusion takes place.
However, they belong respectively to two different forms in the life-history of the plants; the leaves of the mosses are borne by the gametophyte, those of the club-mosses by the sporophyte.