. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. EXCRETORY SYSTEM IN DIGENEA. 331 O C. furcicauda in having three flame cells instead of two in the first (anterior) group. The formula for these species is 7 = (3 + 2+2). In Cercaria robusticauda (Fig. 7) there are the same number of flame cells as in C. emarginattz and C. douglasi, but the size of the anteriormost is evident proof of its double nature. Hence the formula for this species is 7 = (i +2+2+2). One of these cells runs into the tail. This species is transitional between the larvae with seven flame cells in three g
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. EXCRETORY SYSTEM IN DIGENEA. 331 O C. furcicauda in having three flame cells instead of two in the first (anterior) group. The formula for these species is 7 = (3 + 2+2). In Cercaria robusticauda (Fig. 7) there are the same number of flame cells as in C. emarginattz and C. douglasi, but the size of the anteriormost is evident proof of its double nature. Hence the formula for this species is 7 = (i +2+2+2). One of these cells runs into the tail. This species is transitional between the larvae with seven flame cells in three groups and C. quattuor-solenata nov. spec. C. quattuor-solenata (Fig. 8) represents a condition in which a full additional flame- cell unit has been provided. Its formula is 8 = (2 + 2 + 2 + 2). Incidentally, the main collecting tubule in this species has been shortened to a minimum, while the four secondary tubules have been length- ened accordingly. In Cercaria rhabdoc&ca nov. spec. (Fig. 9) five fundamental flame-cell groups are found, so that the formula is 10 = (2 + 2 + 2+2+2). The flame-cell arrangement in Cercaria gigas (Fig. 10) is apparently unrelated to any of the foregoing species. Ten flame cells have been found on each side of the body of the cercaria and one in the tail. By inspection the formula would seem to be IO = (2 + I +I + I +I+3 + I). That FIG. 10. Cercaria gigas this may constitute a seven-fold grouping, Faust' dorsal view' show' ... , , ...... ing excretory system on in which two of the groups have divided, is rightsideof body. x 540. supported in part by the fact that the single cells are somewhat larger than the cells of the units where the division has taken place, but the evidence is not entirely con- vincing. In the mature cercaria of this species the flame cell in the tail has no direct connection with the cells or tubules of the body proper. Its outlet is through a simple longitudinal. Please note that these images are extracted from scanned pa
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
