The Journal of experimental zoology . Fig. dianthus. Age, 23 days. Dorsal view (X75).Original third pair is not shown. First pair shows beginningsof secondary branches. In Fig. 15 the opercular character of the knob on L-II is veryevident. The cup of the operculum has a notched edge witheleven serrations and resembles in its character the Serpula typeand not the Hydroides type. The eight dependent (II—2 toII—9) and one independent branch are very prominently developed 46 Charles Zeleny. and evidently all of them retain their respiratory character. Thecorresponding branchia (R-II)
The Journal of experimental zoology . Fig. dianthus. Age, 23 days. Dorsal view (X75).Original third pair is not shown. First pair shows beginningsof secondary branches. In Fig. 15 the opercular character of the knob on L-II is veryevident. The cup of the operculum has a notched edge witheleven serrations and resembles in its character the Serpula typeand not the Hydroides type. The eight dependent (II—2 toII—9) and one independent branch are very prominently developed 46 Charles Zeleny. and evidently all of them retain their respiratory character. Thecorresponding branchia (R-II) on the right side has branchletssimilar to those of the branchia (L-II) on the left side though itshows no opercular modifications. It is similar to the latter anddifferent from all the other branchia? in one essential I, II—I and III show buds of new developing pinnules itspinnules (/. e., the eight dependent ones II—2 to II—9) are all. Fig. dianthus. Age, 34 days. The next to the dorsal branchia on each side. The left oneshows the beginning of the knob of the functional operculum. The right one later drops off and therudimentary operculum regenerates from the remaining stump. well grown, indicating, no doubt, that the organ has reached itslimit of development as a branchia. With the beginning of the opercular differentiation Branchia Ienters on a new period. It increases in size and new branchlets(pmnules) sprout out in rapid succession, the first ones appearingsimultaneously. Thus in Fig. 15, I already has thirteen wellformed pinnules with several buds crowded into a zone at thebase of the terminal filament. Branchia II—i has likewise been Compensatory Regulation. 47 increasing in size and now has 12 pinnules plus a thirteenth bud oneach side Branchia III is also branched but the character of itspinnules is not given in the figure in order that complication maybe avoided. This pair of branchiae is di
Size: 1560px × 1602px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorwi, bookcentury1900, bookdecade1900, booksubjectzoology
