A phylogenetic classification of animals (for the use of students) . lutelyundifferentiated, and from which many side branches (longor short, according to the amount of variation displayed)have diverged. The few of these which are shown in thetable may be taken as representing some of the more im-portant groups of Monera which are known. The inter-mediate forms have become extinct.! The table would be amore correct representation of nature if every line and branchhad been shown bristling with innumerable short twigs,extending in all directions, of different lengths, and many of * All the strai
A phylogenetic classification of animals (for the use of students) . lutelyundifferentiated, and from which many side branches (longor short, according to the amount of variation displayed)have diverged. The few of these which are shown in thetable may be taken as representing some of the more im-portant groups of Monera which are known. The inter-mediate forms have become extinct.! The table would be amore correct representation of nature if every line and branchhad been shown bristling with innumerable short twigs,extending in all directions, of different lengths, and many of * All the straight lines in the table must be regarded as very fine zig-zags, since each ancestral form diverged a little from its In regard to this, consult The Origin of Species, 6ih ed., p. 293. 8 them branched, and giving off twigs in their turn. Thesewould represent different slight modifications or varieties,most of which have died out. They would have addedgreatly to the complication of the table, and can readily beimagined, therefore they have been Fig. 2. Protomyxa aurantiaca, Haeckel, A. The Plasmodium stage. B. Theencysted condition. C. The protoplasm inside the cyst breaking up intomastigopods. D. The mastigopods, set free by the rupture of the cyst, becomingmyxopods, and then uniting to form small Plasmodia. Protomyxa (fig. 2) is decidedly above Protamoeba andothers of the Monera, and has a complicated and veryinstructive life-history,* the main points of which are that amyxopod stage (the plasmodium, fig. 2, A) passes into anencysted condition (fig. 2, B), and then breaks up into anumber of mastigopods (fig. 2, C), each of which afterescaping from the cyst becomes a myxopod (fig. 2, D). * See Haeckel, Studien iiher Moneren; or, Huxleys Invertebrata, p. 81. These then fuse together, in small numbers, to formPlasmodia, such as the first stage, and thus complete thecycle. The life-histories of many of the Myxomycetesexhibit series of stages very closely rese
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectzoology, bookyear1885
