. Text-book of zoology for junior students. Zoology. 116 IXVEIiTEBRATE AXIMALS. present. The water-vascular system consists of two long vessels which run down each side of the body and communicate at each articulation by a transverse vessel, the whole oi)ening in the last joint into a cimtractile vesicle. Each joint, or " ]," is sexu- ally 2>erfect, or hernia]ihriidite, containing male and female I'eproductive , which open on the surface by a small raised aperture, the "generative jioro" (tig. 7.'5, /()â Almost the whole of each of the niatm-e j
. Text-book of zoology for junior students. Zoology. 116 IXVEIiTEBRATE AXIMALS. present. The water-vascular system consists of two long vessels which run down each side of the body and communicate at each articulation by a transverse vessel, the whole oi)ening in the last joint into a cimtractile vesicle. Each joint, or " ]," is sexu- ally 2>erfect, or hernia]ihriidite, containing male and female I'eproductive , which open on the surface by a small raised aperture, the "generative jioro" (tig. 7.'5, /()â Almost the whole of each of the niatm-e joints is filled up by a much-branched uterus. As the head is the true animal, and the numerous joints are only produced by budding, it follows that the entire organism is to be regarded as a kind of colony, constituted by a single sexless zooid. ;. ";:!.â:M(.r|> of T^enindn. a Head and a few following segments of Timia 'ineilloc'; }i A lew segnientn of the same fnrtlier rnuoved from the head; c and (( Segments ijrogressixely fuilher remoi-eil froiri the head,âall of the natural siw ; e I-Iejid of the same, enlarged ; /t A single of the same, with its liranched uterus and lateral genital jiiire, enlarged two diameters; /Embryo of J'.r/i;,. bi'fiiUfiris. witli six hofiklets ; ;; nlhiluy,,-, the "cystic" young of J'.e/ioi si:lhivi, with ils hoiikh-ts and surliers, i|-,s wrinkled neck, and its caudal vesii-le, enlaiged. (.\tter Leuckart, Van Beneden, and AVeinland.) or " nurse " and numerous sexual zooids, produced by budding from the former. Tlie process of developmentâthat is to say. the process by which this composite organism, commonly known as tlie tapeworm, is pro- ducedâis a very remarkable one, and is briefly ,as follows: Each generative segment or joint, as already .said, is herm;i,plirodite, and contains innumerable ov;i. Tliese eggs, however, be de- velo]>ed within the bcdy of the anima
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectzoology, bookyear1885
