The Journal of experimental zoology . body the two opercula which develop are both large andresemble the functional in general character though differing fromit in particulars. The same thing is further indicated by thepossibility of an explanation on this basis of the complicated resultsobtained when both opercula are cut off. It has been shown(p. 61) that assuming such an interaction between the operculaas here given we can explain the development of two functionalsin one group and the reversal of the opercula in the other by theearlier dropping off of the functional stalk in the former grou
The Journal of experimental zoology . body the two opercula which develop are both large andresemble the functional in general character though differing fromit in particulars. The same thing is further indicated by thepossibility of an explanation on this basis of the complicated resultsobtained when both opercula are cut off. It has been shown(p. 61) that assuming such an interaction between the operculaas here given we can explain the development of two functionalsin one group and the reversal of the opercula in the other by theearlier dropping off of the functional stalk in the former group ascompared with the latter, giving the bud of the functional side inthe first case an equal chance in the competition with the oppositeone, which chance it does not possess in the second case. IV. THE RATE OF DIFFERENTIATION DURING REGENERATION OFTHE OPERCULA IN THE SERPULID, APOMATUS. The effect of the size of the piece upon the rate of regenerationof the opercula may be very conveniently studied in this species 78 Charles B Fig. ampullifera. A—Operation: Branchial circlets cast off at breaking joint. Body of three most dorsal branchia of right side 9 days after operation. No opercular differentiation(X45). B—Operation: Same as in A. Figure of regenerating right branchial circlet 6 days afteroperation. No opercular differentiation. C—Left branchial circlet of same ( X 62). D—Opera-tion: Branchial circlets thrown off at breaking joint. Body posterior to third thoracic segment days after operation. Note opercular differentiation ( X 62). E—Operation: Same as D,except that thoracic cut is at second segment. Figure shows the regenerating left branchial circlet 6days after operation. Note beginning of opercular enlargement. Compensatory Regulation. 79 because there is a very definite line of cleavage along which thebreak always takes place, and similar materials may be assumedto exist at the regenerating surface at the ti
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Keywords: ., bookauthorwi, bookcentury1900, bookdecade1900, booksubjectzoology
