Vulgar words in The Evolution of Man — Volume 1 (Page 1)
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~ ~ ~ Sentence 362 ~ ~ ~
GONADS: the sexual glands.
~ ~ ~ Sentence 2,125 ~ ~ ~
Quite in harmony with this new conception of the EQUIVALENCE OF THE TWO GONADS, or the equal physiological importance of the male and female sex-cells and their equal share in the process of heredity, is the important fact established by Hertwig (1875), that in normal impregnation only one single spermatozoon copulates with one ovum; the membrane which is raised on the surface of the yelk immediately after one sperm-cell has penetrated (Figure 1.25 C) prevents any others from entering.
~ ~ ~ Sentence 3,161 ~ ~ ~
In Sagitta and other worm-like animals the two coelom-pouches (presumably gonads or sex-glands) are separated by a complete median partition, the dorsal and ventral mesentery (Figure 1.78 dm and vm); but in the vertebrates only the upper part of this vertical partition is maintained, and forms the dorsal mesentery.
~ ~ ~ Sentence 3,329 ~ ~ ~
a aorta, af anus, au eye, b lateral furrow (primitive renal process), c coeloma (body-cavity), d small intestine, e parietal eye (epiphysis), f fin border of the skin, g auditory vesicle, gh brain, h heart, i muscular cavity (dorsal coelom-pouch), k gill-grut, ka gill-artery, kg gill-arch, ks gill-folds, l liver, ma stomach, md mouth, ms muscles, na nose (smell pit), n renal canals, u apertures of same, o outer skin, p gullet, r spinal marrow, a sexual glands (gonads), t corium, u kidney-openings (pores of the lateral furrow), v visceral vein (chief vein).
~ ~ ~ Sentence 3,459 ~ ~ ~
But in the two lowest classes of our stem, the acrania and cyclostoma, they consist merely of simple sexual glands or gonads, the ovaries of the female sex and the testicles (spermaria) of the male; the former provide the ova, the latter the sperm.
~ ~ ~ Sentence 3,460 ~ ~ ~
In the craniota we always find only one pair of gonads; in the amphioxus several pairs, arranged in succession.
~ ~ ~ Sentence 3,462 ~ ~ ~
These segmental pairs of gonads are the original ventral halves of the coelom-pouches.
~ ~ ~ Sentence 3,469 ~ ~ ~
As a fact, the articulation is by no means chiefly determined and caused by the skeleton, but by the muscular system and the segmental arrangement of the kidneys and gonads.
~ ~ ~ Sentence 3,900 ~ ~ ~
In the amphioxus each of the former makes a muscular pouch, and each of the latter a sex-pouch or gonad.
~ ~ ~ Sentence 4,213 ~ ~ ~
On the other hand, the ventral parts give rise, from their uppermost section, to the pronephridia or primitive-kidney canals, and from the lower to the segmental rudiments of the sexual glands or gonads.
~ ~ ~ Sentence 4,278 ~ ~ ~
The segmentation in the ventral cavity affects the following principal systems of organs: 1, the gonads or sex-glands (gonotomes); 2, the nephridia or kidneys (nephrotomes); and 3, the head-gut with its gill-clefts (branchiotomes).
~ ~ ~ Sentence 4,284 ~ ~ ~
This cenogenetic process is so old that the cavity seems to be unsegmented from the first in all the craniotes, and the rudiment of the gonads also is almost always unsegmented.
~ ~ ~ Sentence 4,293 ~ ~ ~
These segmental gonads are originally nothing else than the real gonotomes, separate body-cavities, formed from the hyposomites of the trunk.
~ ~ ~ Sentence 4,294 ~ ~ ~
The gonads are the most important segmental organs of the hyposoma, in the sense that they are phylogenetically the oldest.
~ ~ ~ Sentence 4,304 ~ ~ ~
As the first traces of the gonads make their appearance in the lining of these middle plates nearer inward (or the middle) from the inner funnels of the nephro-canals, it is better to count this part of the mesoderm with the hyposoma.
~ ~ ~ Sentence 4,321 ~ ~ ~
The gill-clefts, which originally in the older acrania pierced the wall of the fore-gut, and the gill-arches that separated them, were presumably also segmental, and distributed among the various metamera of the chain, like the gonads in the after-gut and the nephridia.