H.—4.

Plate ll.—lllustrates the Tape-worm or T^nia Stage of T^nia sebialis as found in the Dog. Fig. 1. The tape-worm (Tcenia serialis), reared in a dog which had been fed with the bladder-worm (Ccenurus serialis). It consists of a head and neck, together with a series of joints or segments, increasing in size from the head towards the hind end. The joints, a, b, c, d, are shown on a larger scale in figs. 6-9. One free joint ( = proglottis) is shown natural size. Fig. 2. The head and neck and first few joints of the same tape-worm. Magnified 28 diameters. Fig. 3. The head of a similar tape-worm, showing the flattened form, the four suckers, and the rostellum with the crown of hooks. Magnified 28 diameters. Fig. 4. Crown of hooks of a similar tape-worm, drawn with camera lucida. Magnified 146 diameters. Fig. 5. Free joints or proglottides of Tcenia serialis in different states of contraction, as observed in proglottides when crawling. Fig. 6. The ninety-first segment (a) of the tape-worm in fig. 1. Shows the reproductive organs shortly before the formation of the eggs: t., testes; v.d., vas deferens ; g., germarium (germ-forming gland) of right side; y., vitellarium, or yolk-forming gland ; v., uterus ; v., vagina ; f., genital sinus ; «., excretory vessel. Magnified 13 diameters. Fig. 7. The hundred-and-fourth segment of the same tape-worm. Shows the first branches developed from the uterus as the primitive eggs pass into it. Magnified 13 diameters. Fig. 8. About the twentieth segment from the end, showing the uterus with its numerous branches. This segment is slightly contracted. Magnified 6J diameters. Fig. 9. One of the last segments (d). The uterus and its branches are crowded with eggs containing mature embryos. Magnified 6J diameters. [Figs. 6-9 are reduced from drawings made with camera lucida. Much care was taken to secure accuracy in the details of the branches of the uterus.] Fig. 10. Segment of Tcenia ccenurus, for comparison with figs. 8 and 9. After Leuckart. Said to be magnified 10 or 15 diameters. Fig. 11. A small (a) and large (b) hook from Tcenia ccenurus. Copied from Leuckart for comparison with fig. 12. Magnified 280 diameters. Fig. 12. The corresponding hooks of Tcenia serialis. Drawn with camera lucida. Magnified 280 diameters. Postscript. —The writer finds that, contrary to his expectation, the engraver has slightly reduced the scale of the figures. The figures are therefore smaller than is stated above ; thus in Plate I. thay have been reduced in the proportion from 100 to 97, and in Plate 11. from 100 to 93.

[Approximate Cost of Paper.— Preparation, nil; printing (2,000 copies), £1110s.]

Authority : Geobge Didsbuby, Government Printer, Wellington.—lBB9.

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