The female's various emulsions of coyness and display are motivated by posterior pituitary and gonad hormones in alliance.
They may be rather gonad unstable with a corresponding instability of the entire endocrine system.
But others display signs of sex differentiation that are to be traced back to an awakening interstitial gonad action.
The male's attitude, aggressive pursuit, is instigated by the compound adrenal and gonad endocrines.
A woman who is gonad deficient with a superior adrenal will suffer from virilism and specialize in the extreme tactics and mythology of the feminist movement.
Among the Capitellidae, which in several respects resemble the Oligochaeta, wide and short gonad ducts coexist in the same segments with nephridia, the latter being narrower and longer.
In this category are included (by Goodrich and Lankester) the gonad ducts of the Oligochaeta, certain funnels without any aperture to the exterior that have been detected in Nereis, &c.
Burger) in coelomic spaces close to nephridial funnels, which have, however, no relation to the gonad ducts.
In these and other Chaetopods the coelom is also put into indirect relations with the outside world by the nephridia and by the gonad ducts.
Polychaeta, gonadducts in the Capitellidae, the gonad ducts of the leeches.
To this category will belong the oviducts in Teleostean fishes and probably the gonad ducts in several groups of invertebrates.
In Lumbricus the connexion is a little closer; the funnel of the nephridium, in the segments in which the funnels of the gonad ducts are to be developed, persists and is continuous with the gonad duct funnels on their first appearance.
It is possible that we have here gonad ducts distinct from nephridia which at the time of sexual maturity do open on to the exterior.
Nephridia sometimes of the type of those of the Oligochaeta; in other cases short, wide tubes with a large funnel serving also entirely or in part as gonad ducts.
The Oligochaeta contrast with the Polychaeta in the general presence of outgrowths of the septa in the genital segments, which are either close to, or actually involve, the gonads, and into which may also open the funnels of the gonad ducts.
To this category belong certain sacs and pouches in many, perhaps most, genera of the Oligochaeta family, Eudrilidae, and possibly the gonad ducts in the Hirudinea.
The gonad ducts are male and female, and open opposite to or, rarely, alongside of the gonads, whose products they convey to the exterior.
The function of nitrogenous excretion was not therefore a necessary part of the view--though it may be pointed out that there are grounds for believing that the gonad ducts are to some extent also organs of excretion (see below).
This is shown by the labial commissure and pedal cords of the nervous system, by the opening of the gonad into the right kidney, and by other points.
The essential reproductive organ or gonad consists of both ovarian and testicular cells (see fig.
This fact led Cuvier erroneously to the belief that a duct existed leading from the gonad to this papilla.
The gonad has no accessory organs and except in Neritidae no duct, but discharges into the right kidney.
In the most primitive existing Gastropods the gonadopens into the right kidney (Patellidae, Trochidae, Fissurellidae).
The gonad is transversely wrinkled and lies between the aorta and the intestine, extending from the pericardium to the anterior end of the body.
A simple gonaduct on each side arises from the gonad near its posterior end and passes first forwards, then backwards, and lastly outwards to the external opening in the pallial groove, anterior to the renal aperture.
The chief difference is that the gonad or generative portion of the coelom is single and median, opening into the pericardium by a single posterior aperture.
The gonad of the left side had the tubular structure of a testis, but showed no signs of active spermatogenesis, but in its lower part contained two ova.
Even in these cases the moth when developed showed the original characters of the sex to which belonged the caterpillar from which it came, although it was carrying a gonad of the opposite sex.
The left and larger gonad had a quite similar structure, but at its lower end were found two ova enclosed within a follicular epithelium.
In microscopic structure the right gonad resembled a testis consisting entirely of tubuli lined by an epithelium consisting of a single layer of cells.
With regard to the last case it is to be remarked that though the gonad on the right side was entirely male, there was no unilateral development of male characters.
There was a gonad on each side, that of the right about one-fourth the size of that on the left.
The gonad itself appears to represent a single median or bilateral organ.
The gonads are on the radial canals or on the stomach (Ptychogastridae), and each gonad may be divided into two by a longitudinal sub-umbral muscle-tract.
Solenomya, in which the gonad opens into the reno-pericardial duct.
In Arca, in Anomiidae and in Pectinidae the gonad opens into the external part of the renal tube.
The gonads open into the kidneys and the right gonad extends into the mantle.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "gonad" in a variety of sentences. We hope that you will now be able to make sentences using this word.
