. Text-book of embryology. Embryology. Fig. 137.âAdvanced embryo of Astacus jiumatilis viewed from the ventral side. The abdomen and hinder part of the thorax are cut off and spread out separately. (After Beichenbaoh.) ab, abdomen; , rudiment of branchial cavity; , deuterocerebrum ; ex, opening of excretory organ ; lab, labrum ; â , protocerebrum; oc, eye-stallc; th, thoracic legs; , thoracic ganglia ; , tritucerebrum. Fig. 138.âTwo ommatidia from the eye of a newly-hatched crayfish in longitudinal sec- tion. (After Reichenbach.) com, cornea ; , corneal cells ; crys,
. Text-book of embryology. Embryology. Fig. 137.âAdvanced embryo of Astacus jiumatilis viewed from the ventral side. The abdomen and hinder part of the thorax are cut off and spread out separately. (After Beichenbaoh.) ab, abdomen; , rudiment of branchial cavity; , deuterocerebrum ; ex, opening of excretory organ ; lab, labrum ; â , protocerebrum; oc, eye-stallc; th, thoracic legs; , thoracic ganglia ; , tritucerebrum. Fig. 138.âTwo ommatidia from the eye of a newly-hatched crayfish in longitudinal sec- tion. (After Reichenbach.) com, cornea ; , corneal cells ; crys, crystalline cone; , crys- talline cone cells; rh, rhabdome shimmering through the retinula; ^g, pigment cells. In the basal part of the rudiment of the antenna a sac appears, which is the rudiment of the excretory organ {ex, Fig. 137). This sac appears to be similar to one of the coelomic sacs of the abdomen, to it is added a large ectodermic pocket which forms the thin-walled ureter. Soon afterwards the rudiments of the abdominal feet, or pleopods, make their appearance; and in the bifurcated antennule there is an ecto- dermic pit to be seen, which is the beginning of the auditory 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 MacBride, E. W. (Ernest William), 1866-1940; Kerr, John Graham, 1869-; Heape, Walter, 1855-1929. London : Macmillan
Size: 1170px × 2137px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpubli, booksubjectembryology
