. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CONDUCTION OF CORTICAL CHANGE 27 be associated in order that the fertilization of one shall prevent the fer- tilization of the other? Is mere contact of the surfaces of two frag- ments within the outer membrane sufficient or is fusion necessary? In contrast with our extreme cases of complete separation and complete fusion, which can be identified with certainty and in which the results are clear cut, it is difficult to tell by observation in the border line cases in which the two fragments are in contact precisely what degre
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CONDUCTION OF CORTICAL CHANGE 27 be associated in order that the fertilization of one shall prevent the fer- tilization of the other? Is mere contact of the surfaces of two frag- ments within the outer membrane sufficient or is fusion necessary? In contrast with our extreme cases of complete separation and complete fusion, which can be identified with certainty and in which the results are clear cut, it is difficult to tell by observation in the border line cases in which the two fragments are in contact precisely what degree of fu- sion has taken place. Fragments which are in contact but not fused at the time of insemination usually fuse soon after fertilization. Although no statement can be made at present as to the minimum degree of contact or fusion necessary to transmit the impulse, the following experiments throw some light on the question. Fifteen eggs were cut into two fragments which remained separate for more than a minute and then came together so that at the time of insemination they are classed as (1) touching, (2) in good contact, or (3) fused at a narrow neck, the neck being from less than ten to thirty microns through. The eggs are 200 microns in diameter. In five cases the fragments were touching. In four of these cases one sperm entered each fragment. The fragments subsequently fused, but retained an ectoplasmic partition and separated at the time of cleavage, each com-. 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; Lillie, Frank Rattray, 1870-1947; Moore, Carl Richard, 1892-; Redfield, Alfred Clarence, 1890-1983. Woods Hole, Mass. : Marine Biological Laboratory
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
