Journal of experimental zoology . ge. F. inajalis 9 X Menidia menidia notaia cf: June 30 andJuly 1. Nearly all the eggs cleaved and developed normallyup to early periblast stages, when the great majority died. Sevenembryos continued to develop and were isolated and well caredfor. These grew well and developed pigmented eyes, oticvesicles, many somites, pulsating string heart; but no circulationwas established. The chromatophores of the two species in-volved are so similar that it was not possible to determine thepaternal influence. F. majalis 9 X Poronotus triacanthus cf .• June 30 and July 14
Journal of experimental zoology . ge. F. inajalis 9 X Menidia menidia notaia cf: June 30 andJuly 1. Nearly all the eggs cleaved and developed normallyup to early periblast stages, when the great majority died. Sevenembryos continued to develop and were isolated and well caredfor. These grew well and developed pigmented eyes, oticvesicles, many somites, pulsating string heart; but no circulationwas established. The chromatophores of the two species in-volved are so similar that it was not possible to determine thepaternal influence. F. majalis 9 X Poronotus triacanthus cf .• June 30 and July 14-In both experiments the majority of cleaving eggs developedadvanced embryos with well differentiated head parts, the eyesbeing large and heavily pigmented (fig. 6). The blastoporenever successfully closed; a short movable tail developed; thechromatophores showed no trace of the paternal influence; noheart beat was visible and no pericardium appeared. Thesecurious embryos appeared to be specific for this cross. 530 H. H. NEWMAN. Fig. 5 Type of retarded embryo from Fundulus majalis 9 X Menidia beryl-Una cerea cf (at maximum stage of development, five days). The embryonicshield () is short and stands high above the yolk and the germ-ring ()is thick and well defined. Black pigment granules have begun to appear. Fig. 6 Typical embryo from Fundulus majalis 9 X Poronotus triacanthuscf, showing persistent germ-ring () and rudimentary tail (t.). This stageis a week old and at its maximum phase of development. CROSSES WITH THE EGGS OF CYPRINODON VARIEGATUS Cyprinodon is a small brackish water fish commonly calledthe short minnow or rainbow minnow. The spawning habits(described by Newman, 07) are very similar to those of F. heter-oclitus and other members of that genus. The eggs are smallerthan those of any of the Fundulus species, being on the averageless than mm. in diameter. They are covered with a fibroussticky coat similar to that of F. heteroclitus. The yolk is al
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1904
