Their extreme reduction in form and loss of sexuality may be correlated with the saprophytic habit, the proteids and other organic material required for the growth and reproduction being appropriated ready synthesized, the plant having entirely lost the power of forming them for itself, as evidenced by the absence of chlorophyll.
The equable temperature of these cellars and their freedom from drought is one cause of their great success; to this must be added the natural virgin spawn, for by continually using spawn taken from mushroom-producing beds the potency for reproduction is weakened.
For very refined work, however, the irregularities in the reproduction of the reseau may be studied by comparing the measures of the original reseau with the mean of corresponding measures of a number of photographed copies of it.
In the last section (xl.-xlviii.), put as a vision, the temple is to be rebuilt, in dimensions and arrangements a reproduction of the temple of Solomon (cf.
Presbyterianism in the United States is a reproduction and further development of Presbyterianism in Europe.
Instruments such as the telautograph and telewriter are apparatus for transmitting a facsimile of handwriting inscribed on a paper at one end of a line, the reproduction being made automatically at the other end of the line at the same time that the message is being written.
As already stated, there occur in the Hydromedusae two distinct types of person, the polyp and the medusa; and either of them is capable of non-sexual reproduction by budding, a process which may lead to the formation of colonies, composed of more or fewer individuals combined and connected together.
- All known hydropolyps possess the power of reproduction by budding, and the buds produced may become either polyps or medusae.
Reproduction and Ontogeny of the Hydromedusae.
Nearly every possible method of reproduction occurs amongst the Hydromedusae.
In this way we may distinguish, first, vegetative reproduction, the result of discontinuous growth of the tissues and cell-layers of the body as a whole, leading to (I) fission, (2) autotomy, or (3) vegetative budding; secondly, germinal reproduction, the result of the reproductive activity of the archaeocytes or germinal tissue.
The only one of these possible modes of reproduction not known to occur in Hydromedusae is parthenogenesis.
Protohydra is a marine genus characterized by the absence of tentacles, by a great similarity to Hydra in histological structure, and by reproduction by transverse fission.
It is in these parasitic forms that we meet with the method of reproduction by sporogony described above.
The individual is the product of sexual reproduction; a person is an individual of lower rank, which may be produced asexually.
These first unscientific ideas of a genesis of the permanent objects of nature took as their pattern the process of organic reproduction and development, and this, not only because these objects were regarded as personalities, but also because this particular mode of becoming would most impress these early observers.
Since a finite number of particles is only susceptible of finite transpositions, it must happen (he says), in an eternal duration that every possible order or position will be tried an infinite number of times, and hence this world is to be regarded (as the Stoics maintained) as an exact reproduction of previous worlds.
The term Cryptogam is archaic, implying a hidden method of reproduction as compared with the obvious method represented by the flower of the Phanerogam; with the aid of a good microscope it is, however, easier to follow the process of fertilization.
Both sexual and asexual reproduction occur, but there is usually no definite succession of the two modes, marking that alternation of sexual generation (gametophyte) and asexual generation (sporophyte) which characterizes the higher groups.
It may be that in particular cases particular modes of cultivation disfavour the host; or that the soil, climate or seasons do so; but overwhelming evidence exists to show that the principal causes of epidemics reside in circumstances which favor the spread, nutrition and reproduction of the pest, and the lesson to be learnt is, that precautions against the establishment of such favoring conditions must be sought.
/3los, life, and yEVevcs, generation, birth), a biological term for the theory according to which each living organism, however simple, arises by a process of budding, fission, spore-formation of sexual reproduction from a parent organism.
Paired processes on the eighth and ninth abdominal segments may be specialized as external organs of reproduction, but these are probably not appendages.
Nevertheless, the function of reproduction is occasionally exercised by larvae.
The larvae produced by this remarkable method (paedogenesis) of virgin-reproduction are hatched within the parent larva, and in some cases escape by the rupture of its body.
Finds that, though more than 170 sorts of birds are mentioned, 2 yet what is said of them amounts on the whole to very little, and this consists more of desultory observations in illustration of his general remarks (which are to a considerable extent physiological or bearing on the subject of reproduction) than of an attempt at a connected account of birds.
For instance, she one day wished to know the meaning of the following words: PHENOMENON, COMPRISE, ENERGY, REPRODUCTION, EXTRAORDINARY, PERPETUAL and MYSTERY.
About the same time, in a letter to a friend, in which she makes mention of her Southern home, she gives so close a reproduction from a poem by one of her favourite authors that I will give extracts from Helen's letter and from the poem itself:
In a letter to a friend at the Perkins Institution, dated May 17, 1889, she gives a reproduction from one of Hans Christian Andersen's stories, which I had read to her not long before.
Soon after its appearance in print I was pained to learn, through the Goodson Gazette, that a portion of the story (eight or nine passages) is either a reproduction or adaptation of Miss Margaret Canby's "Frost Fairies."
I first tried to ascertain what had suggested to Helen's mind the particular fancies which made her story seem like a reproduction of one written by Miss Margaret Canby.