. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 22O CHILD. [VOL. I. The figures all represent cases of partial division of segments, together with the accompanying abnormalities in the form and position of the genital organs. A classification is difficult, and, I think, unnecessary. In general the more simple and regular cases are discussed first, the complex ones later. Cases resem- bling each other are grouped together as far as possible. Figs. 2-6 are taken from various points near the anterior end of the chain. They all show stages before the appearance of the genital
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 22O CHILD. [VOL. I. The figures all represent cases of partial division of segments, together with the accompanying abnormalities in the form and position of the genital organs. A classification is difficult, and, I think, unnecessary. In general the more simple and regular cases are discussed first, the complex ones later. Cases resem- bling each other are grouped together as far as possible. Figs. 2-6 are taken from various points near the anterior end of the chain. They all show stages before the appearance of the genital organs. These cases, although differing somewhat in form, are grouped together here as furnishing some evidence for the conclusion that the abnormalities of this kind appear at the time the furrows are formed and are not due to a later divi- sion of proglottids. They are certainly as common in these earlier stages as in later ones. Following these are grouped the cases in which the furrows on the two surfaces correspond closely. These include Figs. 7-15, as well as Figs. 2, 3, 5, and 6 of the preceding group. In Figs. 7-15 the genital organs, though they may be abnormal in position, are nearly always fully developed. The remaining figures, 16-23, show cases which are more complex and in which the furrows on the two surfaces do not usually correspond. Moreover, in these cases some of the genital organs are commonly rudimentary or abnor- mally developed. Figure 2. This figure was taken from the extreme anterior end of the body. The furrows between the proglottids have become fairly distinct. As the dorsal and ventral fur- rows correspond exactly in position, only one surface is represented in the figure. Four abnormal segments, a, b, c, and d, are present. The segments a and b are both examples of partial division, one upon the right side, the other on the left. Here the partial furrows end free, not far from the middle of the seg- ment in which they occur, so that the proglotti
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
