. Elements of zoology, to accompany the field and laboratory study of animals. Zoology. ;to ZOOLOGY other cases a mere bud is formed which becomes full of sexual products without ever acquiring resemblance to a jellyfish.' The jellj'fish is the primitive tyi^e which has undergone a reduction in some cases to a gonophore. It is an interesting fact that in certain species sometimes jellyfishes and some- cndJam. Fig. 2G0. â of a medusa \\ith rather more than one-rjuarter of the uml)rolla and manubrium eut awa>' (diasrammatie). The ectoderm is dotted, tlie entoderm {end. Inm.), .st
. Elements of zoology, to accompany the field and laboratory study of animals. Zoology. ;to ZOOLOGY other cases a mere bud is formed which becomes full of sexual products without ever acquiring resemblance to a jellyfish.' The jellj'fish is the primitive tyi^e which has undergone a reduction in some cases to a gonophore. It is an interesting fact that in certain species sometimes jellyfishes and some- cndJam. Fig. 2G0. â of a medusa \\ith rather more than one-rjuarter of the uml)rolla and manubrium eut awa>' (diasrammatie). The ectoderm is dotted, tlie entoderm {end. Inm.), .striated: the hUiek is a membrane be- tween them ; /, eyst containing a little sensory- l)od>'; vl, "; a shelf to diminish the opening of the Viell. Food .s_\-stem : mth, mouth: miib, inanul>rium, ov gullet ; n', radial and eireular eanals, parts of the digesti^â e ra\-it>'. Reprodtietive system : gon, germ-cells. times gonoiihores will be produced. In the bell-hjxlroids the gonophores are encased in a cuticular capsule, but in the tuljularian hydroids thejr are quite naked. There are certain hydromedusse in which the hydroid stage is unknown or known to be lacking. Here belong some jelly- fishes of our Eastern coast, which may become twenty to thirty centimetres in diameter (Fig. 261). Besides these the sea 1 See Fig. , c. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Davenport, Charles Benedict, 1866-1944; Davenport, Gertrude Anna Crotty, 1866- joint author. New York, Macmillan
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectzoology, bookyear1911
