. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. i-56 EDWIN LINTON. opposite the reproductive apertures. On the opposite margin a vitelline mass separates the two vaginse and, like the testes, belongs to both components of the double segment. There is no line of demarcation between the two components. The margins are continuous and smooth everywhere except between the reproductive apertures where the minute serrations, which are characteristic features of younger portions of the strobile, are seen. These ser- rations are inclined towards the extremity of the smaller part,
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. i-56 EDWIN LINTON. opposite the reproductive apertures. On the opposite margin a vitelline mass separates the two vaginse and, like the testes, belongs to both components of the double segment. There is no line of demarcation between the two components. The margins are continuous and smooth everywhere except between the reproductive apertures where the minute serrations, which are characteristic features of younger portions of the strobile, are seen. These ser- rations are inclined towards the extremity of the smaller part, and may be taken as belonging to that part. There is no indication as to which is the older of the two parts, except a slight difference in size. Evidently the reversal took place very soon after the primary segment was formed. Although the segment was not seen attached to its strobile it is not conceivable that the ab- normal condition was assumed after separation from the stro- bile. It is to be noted that there is a reversal in a dorso-ventral direction also, the vagina and oviduct lying above the uterus in one part and below the ute- rus in the other. Or, to state FIG. 2. After Blanchard. Abnorm- thig comparjson in another Way, ality of genital organs of Tcenia saginata. A, C, normal segment; B, abnormal if the specimen were folded to- gether on a hinge-line crossing transversely between the vaginse the two components would not be symmetrical to the plane of their apposed faces, but one would correspond in the position and arrangement of the parts to the other. Abnormalities in cestodes are of common occurrence and the. 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 Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952;
Size: 1102px × 2268px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
