Journal of experimental zoology . ied of anemia. Aloenkhaus made this cross fivetimes but in no case did embryos develop beyond middle germ-ring stages. This result agrees with my experiments of June13 and 29 but differs materially from those of June 19 and (14) made this cross many times but did not attempt torear the hybrids. Loeb, however, got a number of advancedhybrid embryos with eyes, ears, fins, pigment and heart beat;and some developed a circulation which lasted for three or fourdays, but none were observed to hatch. F. heteroclitus 9 X Tautoga onitis d: June It) and July S.
Journal of experimental zoology . ied of anemia. Aloenkhaus made this cross fivetimes but in no case did embryos develop beyond middle germ-ring stages. This result agrees with my experiments of June13 and 29 but differs materially from those of June 19 and (14) made this cross many times but did not attempt torear the hybrids. Loeb, however, got a number of advancedhybrid embryos with eyes, ears, fins, pigment and heart beat;and some developed a circulation which lasted for three or fourdays, but none were observed to hatch. F. heteroclitus 9 X Tautoga onitis d: June It) and July S. Inboth experiments a large per cent of eggs proceeded normally-through cleavage stages and a few reached late germ-ring con-ditions but failed to close the blastopore (fig. 4). Faint pig-mentation appeared but it was not possible to identify the par-ental types of chromatophores. Moenkhaus made this crossthree times with results similar to those just described. iE JOURXAI- OF EXPERIMENTAL ZOOLOGY, VOL. 18, NO. 4 528 H. H. NEWMAN. -y^— Fig. 4 Young hybrid embryo from Fundulus heteroclitus 9 X Tautogaonitis d (four days old). This represents the maximum stage of developmentattained in this cross. The germ-ring {) never completely surrounds theyolk, and very little embryonic differentiation occurs. Note, however, thatchromatophores develop independently of other tissues. CROSSES WITH THE EGGS OF FUNDULUS DIAPHANUS F. diaphanus is a fresh and brackish water species closelyrelated to F. heteroclitus. The egg is a little larger than thatof the latter and is more transparent. The eggs are laid bythe females when clasped by the males, as in F. heteroclitus,and adhere by means of the sticky fibrous covering to aquaticvegetation. Very few eggs of this species were available this yearbut in previous seasons I have crossed F. diaphanus with , F. majalis, and CjTprinodon, all of the family Poecilii-dae, and with Tautogolabrus adspersus. In general the resultsare sim
Size: 1586px × 1575px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1904
