"Acorn-shell (Balanus tintinnabulum). T., tergum; CR., thoracic legs; R., outer shell in section; D., aperture of oviduct; F., mantle cavity; X., depressor muscle of tergum; AN., antennae; OV., ovary; G., depressor of scutum; H., oviduct; AM., adductor muscle of scuta; S., scutum." -Thomson, 1916

Acorn Shell

"Acorn-shell (Balanus tintinnabulum). T., tergum; CR., thoracic legs; R., outer shell in section; D.,…

"Ovaries of Queen and Workers (Apis). A, Abdomen of queen, under side. P, Petiole. o, o, Ovaries. hs, Position filled by honey-sack. ds, Position through which digestive system passes. od, Oviduct. co.d, Vagina. E, Egg-passing oviduct. s, Spermatheca. i, Intestine. pb, Poison bag. pg, Poison gland. st, Sting. p, "Palps" or "feelers" of sting. B, Rudimentary ovaries of ordinary worker. sp, Rudimentary spermatheca. C, Partially developed ovaries of fertile worker. sp, Rudimentary spermatheca." — The Encyclopedia Britannica, 1910

Bee Ovaries

"Ovaries of Queen and Workers (Apis). A, Abdomen of queen, under side. P, Petiole. o, o, Ovaries. hs,…

"Frog with the left side cut away and some of the organs pulled downward. a, aorta leading from the ventricle; b, bladder; c, spinal cord surrounded by the vertebral column of bone; d, small intestine; e, opening of the lungs into the pharynx; h, ventricle of the heart; k, kidney; l, lung; liv, liver; n, brain; ov, ovary; ovd, oviduct; p, pancreas; r, rectum; sp, spleen; st, stomach; t, tongue; si, small intestine; u, left auricle; ur, ureter; v, vena cava; vc, body of vertebra." —Davison, 1906

Dissected Frog

"Frog with the left side cut away and some of the organs pulled downward. a, aorta leading from the…

"Reproductive organs of earthworm. N., Nerve cord; T., anterior testes; S., sacs of setae; R.S., receptacula seminis; s.f., seminal funnels; v.d., vas deferens; ovd., oviduct; ov., ovary; sv., seminal vesicles cut open; VIII.-XV., segmens" -Thomson, 1916

Earthworm Reproductive Organs

"Reproductive organs of earthworm. N., Nerve cord; T., anterior testes; S., sacs of setae; R.S., receptacula…

Diagram of a dissection of the reproductive organs of a snail. a.g., albumen gland; c.d., common or hermaphrodite duct; c.g., hermaphrodite gland; d.s., dart sac; f, flagellum; g, genital aperture; m.g., mucous glands; o, oviduct; p, penis; r.s., receptaculum seminis; v.d., vas deferens.

Snail

Diagram of a dissection of the reproductive organs of a snail. a.g., albumen gland; c.d., common or…