Reproduction by conjugation is also known as isogamy, by fertilization as oogamy.
That nuclear conjugation between cells ever takes place.
Among Conjugatae reproduction is effected solely by means of conjugation of what are literally aplanospores.
Fl Protosiphon, conjugation of stages of conjugation.
It is known that zoogametes, which usually conjugate, may, when conjugation fails, germinate directly (Sphaerella).
Thus among Volvocaceae, a family of Protococcales, while in some of the genera (Chloraster, Sphondylomorum) no sexual union has as yet been observed, in others (Pandorina, Chlorogonium, Stephanosphaera, Sphaerella) conjugation of similar gametes takes place, in others still (Phacotus, Eudorina, Volvox) the union is of the nature of fertilization.
In Sirogonium there is cell-division in the parent-cell prior to conjugation; and as two segments are cut off in the case of the active gamete, and only one in the case of the passive gamete, there is a corresponding difference of size, marking another step in the sexual differentiation.
The assertion of Areschoug that conjugation occurs among zoospores derived from unilocular sporangia, in the case of Dictyosiphon hippuroides, is no doubt to be ascribed to error of observation.
The verb displays a like abundance of trf mary forms with Sanskrit, but the conjugation by periphrasis lit only slightly developed.
It has preserved in the conjugation and in the formation of the plural older forms than the classical Nahuatl itself.
In a few species a sexual process is described, consisting in the conjugation of similar cells (Zygochytrium) or the union of two dissimilar ones (Polyphagus).
The ordinary conjugation is formed quite differently.
T~tU!)O(j cause him to live, from Egyptian dltn1/2-f), and, in its periphrastic conjugation, the same forms of wn, be, and Iry, do.
When two similar zoogametes fuse, the process is conjugation, and the product a zygospore (Gr. ?"vy6, yoke).
Among colonial Desmidiaceae, the break-up of the filament is a preliminary to this conjugation; otherwise the process is the same.
The second conjugation has for endings -of, -ot, -ddo, -ddi; -om, -och, -ddynt; the third -yf, -yt, -ddo, -ddi; -ym, -ych, -ddynt.
Some verbs originally belonging to the conjugation in e r e have, passed over into that in ir; for example t e n e r e gives lenir alongside of tindre, r e man e r e romanir and romandre.
In the gerundive and in the present participle Catalan differs from Provenal in still distinguishing the conjugation in it from that in Cr, resaying, for exampIe~ senhint.
It is an elementary introduction to the study of Hebrew, the first of its kind, in which only the most indispensable definitions and rules have a place, the remainder being almost wholly occupied by paradigms. Moses Kimhi was the first who made the verb paqadh a model for conjugation, and the first also who introduced the now usual sequence in the enumeration of stem-forms. His handbook was of great historical importance as in the first half of the 6th century it became the favourite manual for the study of Hebrew among non-Judaic scholars (1st ed., Pesaro, 1508).
An indefinite article has been formed, and in the conjugation of the verb a great simplicity sets in.
The old perfect of the conjugation in at had t (also i) in the 1st pers.
In Schizosaccharomyces and Zygosaccharomyces, however, we have a fusion of nuclei in connexion with the conjugation of cells which precedes sporangium-formation.
The zygospore becomes surrounded with its own wall, consisting finally of three layers, the outer of which is furnished with spicular prominences of various forms. In Zygnemaceae there is no dissolution of the filaments, but the whole contents of one cell pass over by means of a conjugation-tube into the cavity of a cell of a neighbouring filament, where the zygospore is formed by the fusion of the two FIG.
The conjugation of similar gametes, arising from distinct plurilocular sporangia, was observed by Berthold in Ectocarpus siliculosus and Scytosiphon lomentarius in 1880; and these observations have been recently confirmed in the case of the former species by Sauvageau, and in the case of the latter by Kuckuck.
In these cases, however, the potential gametes may, failing conjugation, germinate directly, like the zoospores derived from unilocular sporangia.
(2) As regards conjugation only two points need be noted here: (a) it employs the form known as the inchoative, that is to say, the lengthening of the radical of the present in verbs of the third conjugation by means of the syllable ex or ix, a proceeding common to Italian, Walachian, Provenal and French, but altogether unknown in Hispanic Romance; (b) the formation of a great number of past participles in which the termination is added; as in Provenal, not to the radical of the verb, but to that of the perfect: tingut from tinch, pogut from poch, conegut from conech, while in Castilian tenido (formerly also tenudo), podido, conocido, are participles formed from the infinitive.
ConjugationC at alan, and especially modern Catalan, has greatly narrowed the domain of the 2nd conjugation in e r e; a large number of verbs of this conjugation have been treated as if they belonged to the 3rd in r e; d e b e r e makes deure, v i d e r e, veure, and alongside of haber, which answers to h a b b r e, there is a form heure which points to h a b ~ r e.
In conjugation there are some notable peculiarities.
Antghi, aghi), has likewise served fur the forination not only of the past participle but also of the infinitive (agher, habere, can only be explained by ach, 3rd person of the perfect); the infinitives with r paragogic (viurer, seurer, plonrer) are not used (viure, seure, ploure ilistead); in the conjugation of the present of the verb essar or esser, the 2iid pers.
Ses formed upon the persons of the plural, while continental Catalan says ets (anciently est), as also, in the plural, scm, seu, instead of som, sou, are to.be noted; tenere has passed over to the conjugation in re (trenda=tendre), but it is at the same time true that in ordinary Catalan also we have hindrer alongside of tenir the habitual form; dicere gives not dir but diure, which is more regular.
Conjugalion.The conjugation of Castilian (and Portuguese) derives a peculiar interest from th~ archaic features which it retains.
Another special feature of CastilianPortuguese is the complete absence of the form of conjugation known as inchoative (intercalation, in the present tense, of the syllable isc or esc between the radical and the inflexion), although in all the other tenses, except the present, Spanish shows a tendency to lay the accent upon the same syllable in all the six persons, which was the object aimed at by the inchoative form.
Certain forms of the conjugation of the verb differ from the Castilian: dar, esiar, haver, saber, poner readily form their imperfects and imperfect subjunctives like the regular verbs in ar and erhavieron (Cast.
But, on the other hand, Portuguese has remained more exclusively Latin in its vocabulary, and, particularly in its conjugation, it has managed to preserve several features which give it, as compared with Castilian, a highly archaic air.
Portuguese conjugation has more that is interesting.
Among the peculiarities of Portuguese conjugation may be rnentioned(1) the assimilation of the 3rd pers.
In conjugation the peculiarities of Gallego are more marked; some find their explanation within the dialect itself, others seem to be due to Castilian influence.
Conjugation of adults has been observed in several species, the most complete account being that of Zederbauer on Ceratium hirundinella (marine): either mate puts forth a tube which meets and opens into that of the other (as in some species of Chlamydomonas and Desmids); the two cell-bodies fuse in this tube, and encyst to form a resting zygospore.
The Syriac verb is remarkable for having entirely lost the original passive forms, such as in Arabic can be formed in every conjugation and in Hebrew are represented by the Pual and Hophal.
The stability of benzene is ascribed to this conjugation.'
Further, most if not all forms of Sporozoa 'undergo sexual conjugation at some period or other of the life-cycle.
The one in which sexual conjugation occurs.
Moreover, it is very probable that conjugation occurs soon after the arrival of the parasites in their specific invertebrate host; and this act may perhaps give rise to an aflagellar copula, which is gregariniform and comparable to an ookinete.