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