Outlines of comparative physiology touching the structure and development of the races of animals, living and extinct : for the use of schools and colleges . an embryo of the fowl^of the sixthday. It is not onlv divided intotwo lobes, but shows minute coecan its interior. After Muller. ORIGIN OF THE GLANDS. 267. true glandular skeleton, as it has been described in speakingof the conformation of the glands. Would we follow thisgeneration ofthe glandsstep by step,a gland mustbe chosen inwhich the ra-mifications ofthe excretoryduct can beseen amidstthe clearerblastema,from the sim-ple rudimentto
Outlines of comparative physiology touching the structure and development of the races of animals, living and extinct : for the use of schools and colleges . an embryo of the fowl^of the sixthday. It is not onlv divided intotwo lobes, but shows minute coecan its interior. After Muller. ORIGIN OF THE GLANDS. 267. true glandular skeleton, as it has been described in speakingof the conformation of the glands. Would we follow thisgeneration ofthe glandsstep by step,a gland mustbe chosen inwhich the ra-mifications ofthe excretoryduct can beseen amidstthe clearerblastema,from the sim-ple rudimentto the term ofextreme com-plexity. Inyoung em-bryos of thesheep (fig. 2/4) we can, by the aid ofduct of the parotid stillsimply branched, the seve-ral branches enlarged likebuds at their extremities,and but seldom same thing may be seenin small human embryos(fig. 276). To follow theonward evolution, embryos v successively more and moreadvanced mustbe procured,and, the parotid being re-moved, it is to be examinedwith a low power and as anopaque object (fig. 277).The clearer blastema of thegland now appears dark,and the excretory duct, Fig. 273.—Ramifications of the bronchi from theembryonic Falco tinnunculns, to show the way in wh>cnthey sprout as blind canals. Both figures are magnifiedabou
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectzoology, bookyear1870
